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SD School for the Blind & Visually Impaired - Eye Conditions

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

ABLEPHARON
absence of the eyelids
ABNORMAL RETINAL CORRESPONDENCE
see "anomalous retinal correspondence"
ACCOMMODATION
the adjustment of the eye for seeing at different distances, accomplished by changing the shape of the crystalline lens through action of the ciliary muscle, thus focusing a clear image on the retina
ACCOMMODATION
process by which the refractive power of the lens is increased through contraction of the ciliary muscle (N III), causing an increased thickness and curvature of the lens
ACCOMMODATIVE ESTROPHIA
inward deviation of the eyes characteristically more marked for near than far and increased by ciliary muscle contraction in accommodation
ACCOMMODATIVE EXTROPHIA
outward deviation of the eyes, usually secondary to uncorrected myopia
ACHROMATOPSIA
color blindness; often applied to complete color blindness
AFTER-IMAGE
visual sensation occurring after the stimulus causing it has ceased
AGNOSIA
inability to recognize objects by sight with ability to recognize by touch; a sign of lesions of the angular gyrus of the parietooccipital fissure
AGRAPHIA
(visual) loss of ability to write
ALBINISM
a hereditary loss of pigment in the iris, skin, and hair; usually associated with lowered visually acuity, nystagmus, and photphobia and often accompanied by refractive errors
ALTERNATING CORSS-EYES - SQUINT OR STRABISMUS
deviation of the eyes in which either eye may be used for fixation while the other deviates
AMAUROSIS
nearly obsolete term indicating loss of vision
AMBLYOPIA
poor vision or loss of visual acuity without any apparent disease of the eye
AMBLOYOPIA EX ANOPSIA
poor vision or loss of visual acuity from inaccurate focusing on retina due to refractive errors, cataract; dimness of vision due to disuse of the eye
AMBLYOPIA
subnormal visual acuity without any apparent disease of the eye
ex anopsia
refractive, functional, or strabismic amblyopia now preferred
functional
there is inhibition as in refractive or strabismic amblyopia
organic
caused by organic disease, such as optic atrophy, macular degeneration, or cataract
refractive
arises from a refractive err, particularly a marked difference in refraction of the two eyes (anisometropia)
relative
associated with organic amblyopia upon which is superimposed an inhibition as in strabismic amblyopia
strabismic
associated with crossing of the eyes that occurs before the establishment of normal visual acuity in each eye; there appears to be active inhibition of perception of the retinal image transmitted by one eye
AMETROPIA
refractive defect which prevents the eye in a state of rest from focusing the image of distant objects upon the retina; includes hyperopia, myopia, and astigmatism
ANGIOID STREAKS
abnormality of the elastic layer of Bruch's membrane giving rise to pigmented striations of the ocular fundus; associated with a variety of systemic diseases such as pseudozanthomas elasticum, sickle cell disease, and osteitis deformance (Paget's disease), and a variety of generalized diseases affecting the elastic lamina of blood vessels
ANGLE-CLOSURE GLAUCOMA
ocular abnormality in which the intraocular pressure increases, often quickly, because the anterior aqueous humor is mechanically prevented from reaching the trabecular meshwork
ANGLE OF ANOMALY
in strabismus, the degree an eye deviates from parallelism
ANIRIDA
congenital absence of the iris
ANISEIKONIA
condition in which the ocular image of an object as seen by one eye differs in size or shape from that seen by the other eye
ANISOCORIA
condition in which the pupil of the two eyes are of unequal size
ANISOMETROPIA
condition in which the refractive errors in the two eyes are different
ANKLYOBLEPHARAON
condition in which the margins of the eyelids are fused together
ANOMALOUS TRICHROMATISM
defect of color vision in which there appears to be a deficiency of one of the cone pigments (see also "deuteranomaly", "protoanomaly", "tritanomaly")
ANIRIDIA
absence of iris, usually incomplete, with iris root present
ANOPHTHALMOS
absence of a true eyeball
ANTERIOR CHAMBER
space in front of the eye, bounded in front by the cornea, behind by the iris, filled with aqueous
APHAKIA
absence of the lens of the eye
AQUEOUS
clear, watery fluid which fills the anterior and posterior chambers within the front part of the eye
AQUEOUS FLARE
tyndall beam observed with a biomicroscope when excessive protein is present in the anterior aqueous humor
AQUEOUS HUMOR
fluid that fills the posterior and anterior chambers
ARCUATE SCOTOMA
area of blindness in the field of vision of characteristic are shape caused by interruption of a nerve fiber bundle in the retina; most often seen in glaucoma
ARGYOSIS
Silver deposits in the conjunctive, corneal epithelium, stroma, and Descemet's membrane after long term use of silver-containing eye drops
ASTEROID HYALOSIS
fixed opacities composed of a calcium lipid complex that occur in an otherwise normal vitreous body; there are no symptoms
ASTHENOPIA
eye fatigue caused by tiring of the internal and external muscles
ASTIGMATISM
refractive error which prevents the light rays from coming to a single focus on the retina because of different degrees of refraction in the various meridians of the eye
ATROPHIC EYEBALL
degenerated sightless eyeball
ATROPHY, OPTIC
degeneration of the optic nerve
AVULSION OF CARUNCLE
term usually applied to a laceration involving inner one-sixth (lacrimal portion) of lower eyelid with rupture of the inferior canaliculus
BAND KERATOPATHY
deposition of calcium edema, often associated with sudden prolonged increase in intraocular pressure or wearing of contact lenses for an excessively long period (Scattler's veil)
BELL'S PALSY
peripheral paralysis of the facial nerve (N VII)
BELL'S PHENOMENA
upward and outward deviation of the eyes occurring with forcible closure of the eyelids or sleep
BERGMEISTER'S PAPILLA
small mass of glial cells that surround the hyaloid artery in the center of the optic disk; on occasion it persists and obliterates the physiologic cup of the optic disk
BI-CONVEX
two surfaces each of which is part of the outer surface of a sphere
BINOCULAR
pertaining to both eyes
BINOCULAR VISION
the ability to use the two eyes simultaneously to focus on the same object and to fuse the two images into a single image, which gives a correct interpretation of its solidity and its position in space, important in depth perception
BIOMICROSCOPE
microscope for examining the eye and consisting essentially of a dissecting microscope combined with a light source that projects a rectangular light beam that can be changed in size and focus
BITEMPORAL
pertaining to both temples, as bitemporal hemianopsia-blindness in the outer or temporal half of each visual field
BITOT'S SPOT
highly retractile mass with silver-gray hue and having a foamy surface that appears on the bulbar conjunctiva in Vitamin A deficiency
BLEPHARITIS
inflammation of the margin of eyelids; occurs in squamos (seborrheic) ulcerative forms
BLEPHAROCHALASIS
relaxation of the skin of the eyelid due to atrophy of the elastic tissue; the upper eyelid is commonly involved and a fold of tissue hangs over the lid margin
BLEPHAROPHIMOSIS
narrowing of the palpebral fissure, often associated with excessive distance between the inner canthi and drooping of the upper eyelid (Blepharoptosis)
BLEPHAROPLASTY
plastic surgery of the eyelids
BLEPHAROPTOSIS
drooping of the upper lid due to paralysis of the oculomotor (N III) nerve or the sympathetic nerves or to excessive weight of the upper lids
BLEPHAROSPASM
tonic spasm of the orbicularis oculi muscle; spasm of the orbicular muscle of the eyelids
BLIND SPOT
the part of the visual field corresponding to that part of the optic fundus where the optic nerve enters is the physiological blind spot. In disease, it corresponds to an area in the retina which does not function. This term applies to normal eye, not to diseased area.
BLINDNESS
inability to see; defined by Internal Revenue Service as reduction of best corrected visual acuity to 20/200 or less in better eye or restriction of the visual field to 20 degrees or less; defined by Social Security Agency as reduction of vision in best corrected eye to 5/200 or less, in industry, reduction of the best corrected visual acuity to less than 20/200; some states include up to 30 degrees
color
see deuteranopia, protanopia, tritanopia, deuteranomaly, protanomaly, tritanomaly
cortical
caused by a lesion in the cortical visual center
night
inefficient dark adaptation so that vision is markedly reduced in reduced illumination
snow
inability to open eyes to see; secondary to ultraviolet keratitis
BLOWOUT FRACTURE OF ORBIT
comminuted fracture of the roof of the maxillary sinus with prolapse of intraorbital contents into the antrum; there is enophthalmos, blepharoptosis, inability to turn the eye upward, and usually infraorbital anesthesia
BLUE SCLERA
abnormality in which the sclera is thin and has blue appearance arising from the underlying pigmented choroids
BRUSHFIELD'S SPOTS
transient whitish areas in the iris at birth that occurs in Down's Syndrome
BULBAR CONJUNCTIVA
the part of the conjunctiva concerning the anterior surface of the eyeball
BUPHTHALMOS
enlargement of the eye usually occurring as a result of congenital glaucoma; large eyeball (infantile glaucoma, ox eye)
CAMPIMETER
alternative term for perimeter, screen used for visual field defects
CANAL OF SCHLEMM
a circular canal situated at the juncture of the sclera and cornea through with the aqueous is excreted after it has circulated between the lens and the iris and between the iris and the cornea
CANALICULITIS
inflammation of the lacrimal canaliculi; often due to fungus infection
CANDELA
unit of luminous intensity; one candela is defined as the luminous intensity of 1/60 of a square centimeter of projected area of a blackbody radiator operating at the temperature of solidification of platinum
CANDLE POWER
luminous intensity as expressed in candelas
CANTHUS
the angle at either end of the slit between the eyelids, specified as outer, or temporal and inner, or nasal
CARCINOMA
cancer, a malignant growth
CATARACT
any opacity of the lens is a cataract; the opacity arises from either denatured protein or imbibition of fluid by the lens. A condition in which the crystalline lens of the eye, or its capsul, or both, become opaque, with consequent loss of visual acuity.
CELLULITS
an inflammation of soft tissues
CENTRAL ANGIOSPASTIC RETINOPHATHY
condition characterized by separation of the neural retina from the pigment epithelium in the macular area by a serous fluid
CENTRAL VISUAL ACUITY
faculty of the eye to perceive the shape and form of objects in the direct line of vision
CENTROCECAL SCOTOMA
area of blindness in the field of vision involving both the fixation point and the blind spot (cecum); characterizes toxic amblyopia
CHARCOTIS TRIAD
nystagmus, intention tremor, and scanning speech, which occur as a late sign in demyelinating disease, particularly multiple sclerosis
CHEMOSIS
edema of the conjunctiva
CHERRY RED SPOT
apparent color change in the fovea (retinal area of sharpest vision). Results from opacification of the inner retinal layers around it, allowing red color of choroidal circulation to stand out. Occurs in central retinal artery occlusion and Tay-Sachs disease
CHOCKED DISC
marked swelling of the optic disk; sometimes due to a brain tumor
CHORIOD
the vascular tissue of the eye, lying between the retina and sclera, and continuous with the ciliary body and iris in front; it furnishes nourishment to the other parts of the eyeball
CHORIORETINITIS
inflammation of the retina and choroid causing seepage from the blood vessels to accumulate on the retina and sometimes the cornea
CHOROIDITIS
inflammation of the choroids
CHROMATIC ABERRATION
imperfection of an image produced by variations in the refractability of the various wavelengths of white light
CILIA
eyelashes
CILLIARY BODY
portion of the vascular coat between the iris and the choroids; it consists of ciliary muscles and is responsible for the change of shape of lens in accommodation
CIRCINATE RETINOPATHY
rare monocular disorder, mainly of elderly women, characterized by girdle-like zone of small, discrete, coalescing white spots engirdling the macular area
COLLYRIUM
eyewash
COLOBOMA
fissure of a part of the eye; means "something is missing"; congenital cleft due to failure of the eye to complete growth in the part affected
COLOR DEFICIENCY
diminished ability to perceive differences in color; usually for red or green, rarely for blue or yellow
COMMISSURE OR OPTIC CHIASN
the union and crossing of the optic nerve
COMMOTIO RETINA
traumatic lesion of the posterior pole with edema and hemorrhage following contusion of the anterior ocular segment
COMPLEMENTARY AFTER-IMAGE
after-image in which the hue is approximately complementary to the hue of the sensation produced by the original stimulus
COMPLEMENTARY CHROMATICITIES
pairs of different samples of light that produce an achromatic (colorless) stimulus when combined in suitable proportions
COMPLEMENTARY COLORS
pairs of samples of light that have complementary chromaticities; also the proper relative amounts of luminous flux to produce an achromatic (colorless) mixture
CONCAVE LENS
a lens with hollowed surfaces like the inner aspect of a sphere; having the power to diverge the rays of light; also known as a reducing glass or minus lens, denoted by the sign (-)
CONES AND RODS
two kinds of cells which form a layer of the retina and act as a light-receiving media. Cones are concentrated at the macula, and decreasing toward the periphery. Cones are concerned with visual acuity and color discrimination; rods, concentrated at the periphery and decreasing toward the macula are concerned, with motion and vision at low degrees of illumination (night vision).
CONGENITAL
present at birth
CONGRUOUS FIELD DEFECTS
visual field defects that are exactly the same in extent and intensity in both eyes; characterizes lesions in the optic radiation and occipital cortex
CONICAL CORNEA
keratoconus
CONJUGATE MOVEMENTS
paired movements, thus when looking at the right, the external rectus muscle of the right eye pairs up with the internal rectus of the left eye
CONJUGATE OCULAR MOVEMENTS
similar ocular movements of both eyes such as eyes right, eyes down, eyes left, eyes up
CONJUNCTIVA
mucous membrane which lines the eyelids and covers the front part of the eyeball
CONJUNCTIVITIS
inflammation of the conjunctiva
CONSENSUAL LIGHT REFLEX
constriction of the pupil in the fellow eye when the retina is stimulated by light
CONTACT OR CORNEAL LENSES
lenses so constructed that they fit directly on the eyeball; used for the correction of vision in cases having a cone-shape cornea and for cosmetic reasons. Corneal lenses are also used after cataract (lens) extraction to replace the lens removed from the eye. They provide less distortion and image size difference from the other eye than spectacles would.
CONUS OF OPTIC DISK
abnormality in which the choroids and retinal pigment epithelium do not extend to the optic disk, allowing the sclera to be observed ophthalmoscopically at its margin
CONVERGENCE
the act of bringing the two eyes inward as in looking at a near object. The process of directing the visual axes of the two eyes to a near point, with the result that the pupils of the two eyes are closer together.
CONVEX LENS
a lens with surfaces like those of part of a sphere, having the power to converge the rays of light and to bring them to focus; also known as a magnifying, hyperoptic or plus lens, denoted by the sign (+)
CORECTOPIA
displacement of pupil from its normal position
CORNEA
the clear transparent portion of the external coat of the eyeball forming the front of the aqueous chamber; also known as the window of the eye
CORNEAL GRAFT
operation to restore vision by replacing a section of the opaque cornea with transparent cornea
CORNEAL ULCER
infiltration of a certain portion of the cornea, followed by suppuration and loss of substance and finally opacity of the spot
CORRESPONDING POINTS
points on the two retinas that have the same directional value in space
COVER-UNCOVER TEST
alternate covering and uncovering of one eye to distinguish between a phoria and tropia
CRALAZION
a cyst or tumor of the eyelid from retained secretion of the Meibomian glands; chronic lipogranuloma of a meibomian gland; inflammatory enlargement of a meibomian gland in the eyelid
CROSS-EYE
a form of strabismus or squint
A and V
cross-eyes in which the eye are closer together in looking up than down (A) or closer looking down than up (V)
CREDE'S PROPHYLAXIS
installation of 1% silver nitrate in the eyes of a newborn infant to prevent gonococcal conjunctivitis
CRYOTHERAPY
procedure carried out with a freezing probe
CRYSTALLINE LENS
a transparent, colorless body suspended in the anterior portion of the eyeball between the aqueous and the vitreous chambers, the function of which is to bring the ray of light to focus
CYCLITIS
inflammation of the ciliary body
CYCLODIALYSIS
surgical procedure for glaucoma to establish a communication between the anterior chamber and the suprachoroidal space
CYCLODIATHERMY
destruction of a portion of the ciliary body by diathermy to reduce the quantity of aqueous humor produced in glaucoma
CYCLOPLEGIA
paralysis of the ciliary muscle giving rise to paralysis of accommodation
CYLCLOPLEGIC
a drug that temporarily paralyses accommodation by putting the ciliary muscle at rest and dilates the pupil; often used to ascertain the error of refraction
CYLINDER
in optics, a lens having no refracting power in one meridian and maximal refracting power at the meridian at right angles to this
CYLINDERICAL LENS
a lens with one surface which is a section of a cylinder (either concave or convex); a lens used for correction of astigmatism
CYST
a growth consisting of fluid within a capsule
DACRYOCYSTORHINOSTOMY
surgical procedure in which mucous membrane of the lacrimal sac is anastomosed with the mucous membrane lining the middle meatus of the nose to establish lacrimal drainage
DACRYOSTENOSIS
abnormal narrow opening of the tear sac
DARK ADAPTATION
the ability of the retina and pupil to adjust to a dim light
DENDRITIC KERATITIS
inflammation of the corneal epithelium by the herpes hominis virus
DENERVATION SUPERSENSITIVITY
sensitivity to neural effect or substance that follows postganglionic interruption of the nerve supply of organs innervated by the autonomic nervous system
DEPTH PERCEPTION
the ability to perceive the solidity of objects and their position in space
DESCEMETOCELE
herniation of the basement membrane of the corneal endothelium
DETACHMENT, RETINAL
separation of the neural retina from the retinal pigment epithelium
DEUTERANOMALY
form of anomalous trichromatism for which there appears to be a deficiency of green-sensitive cones so that there is poor green-purple and red-purple discrimination, green insensitivity, and normal luminosity function
DEUTERANOPIA
form of dichromatism in where there are but two cone pigments present and there is complete insensitivity to green
DEVIATION
eye misalignment caused by extraocular muscle imbalance; one fovea is not directed at the same object as the other. Present even when both eyes are uncovered
Primary
ocular deviation seen in paralysis of an ocular muscle when the noninvolved eye is used for fixation.
Secondary
ocular deviation seen in paralysis of an ocular muscle when the involved eye is used for fixation.
DIALYSIS OF RETINA
separation of the ora serrata of the neural retina from the retinal pigment epithelium
DIAPHANOSCOPY
transillumination of a body cavity, used in ophthalmology to demonstrate the diminution of the pigment in the iris in the female carriers of albinism or in the diagnosis of intraocular tumors
DICHROMATISM
abnormality of color vision in which only two of the three cone pigments are present; mixtures of two, rather than three, components are necessary and sufficient to match all colors (protanopes, red absent; deuteranopes, green absent; tritanopes, blue absent)
DIOPTER
unit of measurement of strength of refractive power of lenses. A lens of one diopter is a lens having a focal distance of one meter, a comparatively weak lens; a two-diopter lens is one having half the focal length of the one-diopter lens or half a meter; a lens of a focal length of four meters is called and 0.25 diopter lens.
DIPOLOPIA
double vision; one object seen as two; double images result when the visual lines of the two eyes are not directed toward the same object, i.e., when one eye deviates (unless the image of the deviating eye is suppressed); double vision simultaneous perception of two grossly dissimilar images.
Crossed double vision
the image arising from the right is observed to the left of the image arising from the left eye; associated with conditions in which the eyes turn outward.
Uncrossed condition
the image of the right eye is to the right of the image belonging to the left eye; observed in conditions in which the visual axes of the eye are directed toward each other as in esotropia.
DISCIFORM DEGENERATION OF MACULA
secondary type of macular degeneration, often arising from abnormalities in the elastic layer of the lamina vitrea.
DISCIFORM DETACHMENT OF RETINA
term commonly applied to separations of the retina in the macular region arising because blood or serous fluid separates the neural retina from the retinal pigment epithelium.
DISCIFORM KERATITIS
stromal type of cornel inflammation, roughly circular in shape, often seen as secondary stromal involvement to herpes simplex keratitis.
DISINSERTION OF RETINA
retinal dialysis at the ora serrata in which the neural retina is separated from the retinal pigment epithemlium.
DISLOCATION OF LENS
condition in which the crystalline lens is completely unsupported by the zonular fibers so that the lens is free, either in the vitreous body or the anterior chamber.
DOYNE'S HONEYCOMB CHOROIDITIS
noninflammatory condition with excrescences (drusen) of the cuticular layer of the lamina vitrea; fundus appears to be studded with yellowish white dots.
DRUSEN
hyaline excrescences of the lamina vitrea.
DRY EYE
keratoconjunctivitis sicca
DUCTIONS
ocular movements of one eye only
DUCTION
a stem word with a prefix to describe turning or rotation of the eyeball (abduction-turning out, adduction-turning in)
DYSLEXIA
psychological abnormality in which despite adequate intelligence, motivation, and, instruction and in the absence of a physical handicap, emotional disturbance, or cultural deprivation an individual fails to master printed and written language.
DYSMETRIA
abnormality of ocular movements in which there is a disturbance in the power to control the range of movement
DYSTROHY, CORNEAL
noninflammatory developmental, nutritional, or metabolic abnormality characterized by the occurrence of opaque material in the central cornea. Salzman's modular inflammatory opacity of the cornea associated with bacterial hypersensitivity, particularly to Mycobacterium tuberculosis.
ECCENTRIC FIXATION
visual abnormality in which a retinal area other than the fovea centralis is used for visual fixation
ECCHYMOSIS
extravagation of blood beneath the skin. A "Black Eye".
ECTASIA
localized bulging of the sclera or cornea. If uveal tissue is involved it is called a staphyloma
ECTROPION
a condition in which there is an eversion (turning inside out) of the eyelids. Turning outward of the margin of the eyelid occurring in spastic, cicatricial, and paralytic forms.
EIKONOMETER
device for measuring the retinal image size in each eye; used in the diagnosis of aniseikonia or a difference in image size of the two eyes, most often arising from a difference in refractive power of the eyes
ELECTRO-OCULOGRAM
ratio of standing potential between retina and cornea in light and dark adaptation
ELECTROMAGNETIC SPECTRUM
range of radiant energy that has a variable frequency and a constant velocity (energy = Planck's constant x frequency)
ELECTRORETINOGRAM
action potential that follows stimulation of the retina
EMMETROPIA
a condition of normal refraction of the eye. The image of distant objects is focused exactly upon the retina when the eye is in a state of rest.
EMPHYSEMA, ORBITAL
air in the orbit; generally follow traumatic rupture of a nasal sinus, particularly the lamina papyracea of the ethmoid bone
ENDOGENOUS UVEITIS
inflammation of the uveal tract arising from causes within the body in contrast to that introduced from outside the body as in injuries (exogenours)
ENDOPHTHALMITIS
inflammation of most of the internal tissues of the eyeball. Purulent inflammation of the intraocular contents.
ENOPHTHALMOS
abnormal recession of the eyeball within the orbit
ENTROPION
a condition in there is an inversion (turning inward) of the eyelid; observed in cicatricial, spastic, and paralytic forms
ENUCLEATION
complete surgical removal of the eyeball
EPIDEMIC KERATOCONJUNCTIVITIS
inflammation of the cornea and conjunctiva by an adenovirus, often adenovirus type 8
EPILATION
removal of hair or eye lashes
EPIPHORA
tearing in which faulty drainage of tears permits their overflow
EPISCLERITIS
localized inflammation of the superficial tissues of the sclera
EPITHELIAL DOWNGROWTH
epithelialization of the interior of the eye that may follow faulty wound healing of the anterior ocular segment
ERYSIPHAKE
instrument that uses a vacuum to grasp the lens in cataract extraction
ESO DEVIATION
inward deviation of the eye
ESOPHORIA
a tendency of the eye to turn inward; latent inward deviation of the eye in which, with binocular vision suspended, the eyes deviate inward
ESOTROPIA
a manifest turning inward of the eye (convergent strabismus or crossed eye)
ESSENTIAL ATROPHY OF IRIS
rare, progressive unilateral disease of the iris in which there is a patchy loss of all layers of the iris, causing a distorted and migrating pupil and often a secondary increase in intraocular pressure.
ETHMOID SINUS
the cavities of air cells within the ethmoid bones; behind the bridge of the nose
EVISCERATION
in ophthalmology, the surgical procedure in which the intraocular contents are removed, retaining the cornea (sometimes) and the sclera
EXOTROPIA
abnormal turning outward from the nose of one or both eyes (divergent strabismus)
EXCITING EYE
in sympathetic opthmalmia, the injured eye from which the irido-cyclitis is transferred to the uninjured eye
EXENTERATION, ORBITAL
removal of all of the orbital tissues, including the eye and its nervous, vascular, and muscular connections
EXFOLIATION OF LENS CAPSULE
condition in which the anterior lens capsule degenerates and appears to be wiped from the lens by the movement of the iris; true exfoliation follows infra red injury to the lens; pseudoexfoliation is more common; the cause is unknown
EXODEVIATION
turning outward of the eyes
EXOPHORIA
latent outward deviation of the eyes in which, with binocular vision suspended, the eyes deviate outward
EXPOPHTHALMOS
abnormal profusion of the eyes
Endocrine
associated with abnormalities of the thyroid gland
Ophthalmoplegic
inability to move the eye because of exophthalmos
Pulsating
associated with a carotid-cavernous fistula
EXOTROPIA
abnormal turning outward from the nose of one or both eyes (divergent strabismus, a manifest deviation)
EXTERNAL RECTUS MUSCLE
one of the six extrinsic muscles of the eye; it moves the eye outward towards the temple
EXTRINSIC MUSCLES
the six external muscles of the eye which move the eyeball; each eye has four recti and two oblique muscles
EYE
sense organ for sight. Receives light imagery and transmits the visual information to the brain. Composed of three major structural layers (corneo-sclera, uvea and retina) and includes the lens, aqueous and vitreous
EYE DOMINANCE
tendency of one eye to assume to major function of seeing, being assisted by the less dominant eye
EYE GROUNDS
Fundi or interior of the eye, i.e., optic nerves, retina, etc. See Fundus.
FIELD OF VISION
the entire area which can be seen without shifting the gaze, usually measured by means of an arc (perimeter) located 330 mm. from the eye
FLARE, AQUEOUS
see Aqueous Flare
FLOATER
object seen in the field of vision that originates in the vitreous body; the most common floaters are muscae volitantes, minute flects of protein seen in bright, uniform illumination
FLUORESCENCE
reradiaton of energy with increase of wavelength by an absorbing substance
FLUX
short form of radiant flux, or luminous flux, according to context
FOCUS
point to which rays are converged after passing through a lens; focal distance is the distance rays travel after refraction before focus is reached
FOOT-CANDLE
unit of illuminance equal to one lumen incident per square foot
FOOT-LAMBERT
unit of luminance
FORNIX
a loose fold of the conjunctiva where the part covering the eyeball meets the conjunctiva lining of the eyelid
FOVEA
small depression in the retina at the back of the eye; the part of the macula adapted for most acute vision
FRUCTOSE 1-0ALDOLASE DEFICIENCY
enzymatic deficiency associated with amaurotic familial idiocy in the homozygote; parents of such children are heterozygotes and have a much less severe enzyme deficiency
FUNDUS
the back of the eye which can be seen with an ophthalmoscope
FUNDUSCOPE
inasmuch as many organs have a fundus, a more precise term for the instrument used in ophthalmoscopy is ophthalmoscope
FUSION
the power of coordinating the images received by the two eyes into a single mental image
Grade 1 simultaneous macular perception (normal correspondence)
ability of the brain to receive and appreciate images from the fovea of each eye simultaneously
Grade 2 fusion with amplitude
blending of the similar images from the two foveas into a single perception
Grade 3 stereopsis
blending of slightly dissimilar images from the two eyes with the perception of depth
GLARE
sensation produced by brightnesses within the visual field that are sufficiently greater than the luminance to which the eyes are adapted to cause annoyance, discomfort, or loss in visual performance and visibility
GLASSES
popular name for spectacles or eyeglasses
GLAUCOMA
increased pressure inside the eye
GLIOMA
malignant tumor of the retina
GONIOPUNCTURE
surgical procedure for the treatment of congenital glaucoma; a small opening is made in the inside meshwork of the eye allowing drainage of the aqueous fluid into the subconjunctival space
GONIOSCOPE
a magnifying device used in combination with strong illumination and a contact glass for examining the angle of the anterior chamber
GONIOTOMY
operation for congenital glaucoma in which the trabecular meshwork in the region of Schlemm's canal is incised
HALLUCINATIONS
perception without external stimulus that may occur in every field of sensation; visual hallucinations are formed when composed of scenes and unformed when composed of sparks, lights, and the like; formed hallucinations characterize temporal lobe disturbances and unformed visual hallucination characterize occipital lobe disorders, particularly migraine
HASSALL-HENLE BODIES
small white hyaline outgrowths on the cornea that occur as a sign of aging
HEMIANOPSIA
blindness of one-half the field of vision of one or both eyes
HETEROCHROMIA OF IRIS
condition in which the irises of the two eyes are not of uniform color
HETEROPHORIA
a constant tendency of the eyes to deviate from the normal position for binocular fixation
HETEROTROPIA
an obvious or manifest deviation of the visual axis of an eye out of alignment with the other eye. Syn. Cross-eye; strabismus
HIPPUS
spasmodic dilation and contraction of the pupil; particularly noticeable with stimulation of light
HISTOPLASMOSIS
infection due to yeast-like fungus organism; caused by inhalation or ingestion of spores of the organism (found in soil or dried excrement of animals)
HOLMGREN'S COLOR TEST
color vision test utilizing colored yarns
HOMONYMOUS
located on the same side; usually refers to visual field defects
HORDEOLUM
a stye; acute inflammation caused by infection of one of glands an eyelash; if chronic it is called chalazion
HOROPTER
plane in space that localizes the visual direction of corresponding retinal points
HUDSON-STAHLI LINE
brown line of iron deposit in the cornea
HYDROPHTHALMUS (CONGENITAL GLAUCOMA)
a rare congenital defect in which the eyeball is abnormally large caused by glaucoma in a young, stretchable eye
HYDROPS OF IRIS
term applied to the vacuolization of the pigment layer of the iris as occurs when these cells are filled with glycogen in diabetes mellitus
HYPEREMIA
increased blood flow
HYPEROPE
a farsighted person
HYPEROPIA, HYPERMETROPIA (FARSIGHTEDNESS)
a refractive error in which, because the eyeball is short or the refractive power of the lens is weak, the point of focus for rays of light from distant objects (parallel light rays) is behind the retina; thus, the accommodation to increase the refractive power of the lens is necessary for distant as well as near vision
Absolute
the amount of hyperopia remaining after the eye exerts its maximal ability to accommodate
Axial
caused by abnormal shortness of the anteroposterior diameter of the eye
Latent
portion of total hypermetropia that cannot be overcome, or the difference between the manifest and total hypermetropia
Manifest
amount of hypermetropia indicated by the strongest convex lens a patient will accept with retaining normal visual acuity
Total
entire hypermetropia, both latent and manifest
HYPERPHORIA
tendency for the eyes to deviate vertically which is prevented by binocular vision
HYPERTELORISM
excessive width between two organs; in ocular hypertelorism there is increased distance between the eyes that is often associated with mental deficiency and exotropia (outward eye deviation)
HYPERTENSION
high blood pressure (due to disease of the arteries, kidney, or heart and other causes)
HYPERTROPHY
increase in the size of an organ
HYPERTROPIA
deviation of the eyes in which one eye is higher than the other
HYPOTONY, OCULAR
diminished ocular pressure
HYSTERICAL AMBLYOPIA
a form of temporary psychic blindness occurring in hysteria
ILLUMINANCE
luminous flux incident per unity of a surface
IMAGE
visual impression of an object formed by a lens or mirror
False
in double vision, the image arising in the deviating eye
Purkinie's
images reflected from the surface of the cornea, the anterior surface of the lens, and the posterior surface of the lens
Real
in optics, the inverted image in which refracted rays pass through the image point
True
in double vision, the image received by the non-deviating eye
Virtual
in optics, the erect image in which the refracted rays do not pass through the image point, but appear to come from it
INCONGRUOUS FIELD DEFECTS
visual field defects that are dissimilar in the two eyes; occur in lesions involving that portion of the visual pathways anterior to the lateral geniculate body
INFERIOR OBLIQUE MUSCLE
one of the six extrinsic muscles of the eye; it moves the eye up and out and rotates it outward
INFERIOR RECTUS MUSCLE
one of the six extrinsic muscles of the eye; it moves the eye down
INFRARED RADIATION
portion of the electromagnetic spectrum that has a wavelength of more than 700nm and less than 10,000nm
INJECTION
a term sometimes used to mean congestion of ciliary or conjunctival blood vessels, redness of the eye
INTERNAL RECTUS MUSCLE
one of the six extrinsic muscles of the eye; it moves the eye inward towards the nose
INTERSTITIAL KERATITIS
a form of inflammation of the middle layer of the cornea; found chiefly in children and young adults, usually caused by transmission of syphilis from mother to unborn child
INTRASCLERAL NERVE LOOP
condition in which a long posterior ciliary nerve loops in the anterior sclera; gives rise to a minute dark spot of uveal tissue on the sclera
IRIDECTOMY
cutting out a part of the iris
Peripheral
removal of a portion of the peripheral iris
Sector
removal of an entire sector, extending usually from the papillary margin to the root of the iris
IRIDENCLEISIS
surgical procedure creating a permanent drainage route from the anterior chamber by wedging iris tissue into a limbal incision to act as a wick
IRIDOCAPSULOTOMY
surgical procedure in which the iris and adherent lens capsule is incised to create a new papillary opening; procedure is necessitated by a cataract extraction in which a large amount of lens capsule remains
IRIDOCYCLITIS
inflammation of the iris and the ciliary body
IRIDODIALYSIS
separation of the base of the iris from the ciliary body; main cause is blunt trauma to the eye
IRIDODONESIS
iris that flops loosely due to lack of normal support from the lens; follows removal or dislocation of lens
IRIDOPLEGIA
paralysis of the iris sphincter
IRIS
colored, circular membrane, suspended behind the cornea and immediately in front of the lens. The iris regulates the amount of light entering the eye by changing the size of the pupil.
IRIS BOMBE'
condition in which the pupil is adherent to the lens so that aqueous humor accumulates in the posterior chamber; iris tends to balloon forward peripherally and it may close the angle, causing secondary glaucoma
IRIS COLOBOMA
iris defect that leaves a gap in the iris tissue; follows iridectomy or occurs as a congenital abnormality
IRITIS
inflammation of the iris; the condition is marked by pain, congestion in the ciliary region, photophobia, contraction of the pupil discoloration of the iris, and is caused by injury, syphilis, rheumatism, gonorrhea, and tuberculosis
ISHIHARA COLOR PLATES
a test for color blindness; based on the ability to trace patterns in a series of multicolored charts
JAEGER TEST
a test for near vision; lines of reading matter printed in a series of various sizes of type
JOULE
unit of energy; ten million ergs; used in comparing lasers or laser beams
KAYSER-FLEISHER RING
golden deposit of cooper in the periphery of the cornea observed in hepatolenticular degenerations (Wilson's disease)
KERATECTOMY
removal of the cornea
KERATIC PRECIPITATES
clumps of leukocytes adhering to the corneal endothelium in uveal tract inflammation; customarily divided into mutton-fat (macrophages), which occur in granulomatous inflammations, and punctuate (lymphocytes), which occur in non-graulomatous inflammations
KERATITIS
inflammation of the cornea; loss of luster and transparency and cellular infiltration
KERATOCELE (descemetocele)
hernia of Descement's membrane through the cornea
KERATOCONJUNCTIVITIS
simultaneous inflammation of the cornea and conjunctiva
KERATOCONUS
cone-shaped deformity of the cornea; a conical profusion of the cornea
KERATOMALACIA
a degenerative softening of the cornea, often occurring in severe Vitamin A deficiency
KERATOME KNIFE
with a triangular blade used for corneal incision
KERATOMETER
instrument for measuring the radius of curvature of the cornea
KERATOMYCOSIS
gray pus-producing corneal ulcer with irregular borders as a result of fungus infection
KERATOPLASTY
transplantation of a portion of the cornea
Lamellar
outer layers are replaced.
Penetrating
entire thickness of a portion of the cornea is replaced.
KERATOPLASTY
See "Corneal Graft"
KERATOTOMY
incision of the cornea carried out in year past to limit the spread of an ulcer
KOEPPE NODULE
accumulation of the epitheloid cells at the papillary margin in granulomatous uveitis
LACRIMAL GLAND
gland which secretes tears; it lies in the outer angle of the orbit
LACRIMAL SAC
the dilated upper end of the lacrimal duct
LACRIMATION
excessive secretion of tears
LAGOPHTHALMOS
condition in which the globe is not entirely covered with the eyelids closed
LAMBERT
unit of luminance
LASER
acronym for light amplification by stimulated emission of radiation; the laser produces a nearly monochromatic and coherent beam of radiation
LENS
a refractive medium having one or both surfaces curved; in the lens of the eye both surfaces are curved; glass or other transparent material is used optically to modify the path of light
Bifocal
spectacles that contain two foci, usually arranged with the focus for distance above and a smaller segment for near below; such lenses are used in the correction of presbyopia and to relieve excessive accommodation in accommodative strabismus of children
Colored
selectively absorb or reflect certain wavelengths of light
Contact
worn beneath the lids
Crystalline
transparent biconvex tissue located behind the pupil and in front of the vitreous
Prism
transparent solid with triangular ends and two converging sides; separates white light into its spectral components and bends rays of light toward its base; used to measure or to correct ocular muscle imbalance
Safety
lens resistant to shattering made either of plastic or by means of casehardening
LENSOMETER
instrument for determining the refractive power of lens
LENTICONUS
rare abnormality of the lens characterized by a cone-shaped protrusion of the lens, usually on the front surface
LEUCOMA OR LEUKONA
a whitish opacity of the cornea. A less marked opacity is a macula, and the most minor type of opacity is a nebula.
Adherent
corneal opacity to which the iris is adherent
LIGHT
that portion of the electromagnetic spectrum that gives rise to a sensation, through stimulation of the retina
LIGHT ADAPTATION
the power of the eye to adjust itself to variations in the amount of light
LIGHT PERCEPTION (LP)
ability to distinguish light from dark
LIMBUS
the junction of the cornea and the sclerotic coat or white of the eye
LOW VISION AIDS
optical devices of various types useful to persons with vision impairment
LUMEN
unit of luminous flux equal to the flux in a unit of solid angle (one steradiam) from a uniform point source of one candela
LUMINANCE
amount of light emanating from an object and producing a sensation of brightnes
LUMINOSITY
ratio of lumens per watt of any kind of radiant energy
LUMINOUS EMMITTANCE
density of luminous flux emitted from a surface
LUMINOUS FLUX
rate of flow of luminous energy
LUX
unit of illuminance equal to one lumen per square meter
LYSOZYME
antibacterial enzyme found in tears, leukocytes, egg albumin, and plants; mainly effective against nonpathogenic bacteria
MACROPHTHALMOS
abnormally large eyeball, resulting chiefly from infantile glaucoma
MACULA
minute corneal opacity
MACULA LUTEA
the small area of the retina that surrounds the fovea and with the fovea comprises the area of distance vision. Syn. Yellow spot.
MEGALOCORNEA
front third of the eye (cornea) is larger than normal (12 mm or more)
MEGOPHTHALMOS
abnormally large eyeball present at birth (congenital)
MEIOBONIAM GLANDS
sebaceous glands of the eyelids
MICROCORNEA
abnormally small cornea, having a diameter of less than 9 mm
MICROPHAKIA
anomaly in which the crystalline lens is abnormally small
MICROPHTHALMIA
condition in which the eyeball is abnormally small
MICROPSIA
disturbance of visual perception in which objects appear smaller than their true size
MICROSCOPIC GLASSES
magnifying lenses arranged on the principal of a microscope, occasionally prescribed for persons with very poor vision
MILLIMICRON
unit of wavelength equal to 10-9 meter; nanometer now preferred term
MIOSIS
condition in which the pupil is constricted
MIOTIC
small pupils
MONOCULAR
relating to one eye as opposed to binocular, which involves both eyes
MORGAGNIAN CATARACT
hypermature cataract, in which the cortex is liquefied, permitting the lens nucleus to float within the capsule
MUSCAE VOLITANTES
flitting flecks darting about in the field of vision caused by opacities in the vitreous humor or erythrocytes in retinal capillaries
MYDRIASIS
increase of pupil size (dilation)
MYDRIATIC
an agent which causes dilation of the pupil
MYOPE
a near-sighted person
MYOPIA
nearsightedness, a refractive error in which, because the eyeball is too long, the point of focus for rays of light from distant objects (parallel light rays) is in front of the retina; thus, to obtain distant vision, the object must be brought nearer to take advantage of divergent light rays (those from objects less than twenty feet away)
Axial
caused by abnormal length of anteroposterior diameter of the eye
Degenerative
stretching of eye structures, with thinning and tearing of sclera, choroid, retinal pigment epithelium and retina, especially in the macular area
Refractive
caused by overpowered optical elements in the eye
NAGEL ANOMALOSCOPE
device for mixing two colors to match a third; used for analysis of color perception
NANOMETER (NM)
unit of wavelength equal to 10-9 (one one-billionth) meter; formerly called millimicron (mu)
NARROW-ANGLE GLAUCOMA
glaucoma arising because opposition of the iris to the peripheral cornea prevents the aqueous humor from draining through the trabecular meshwork
NEAR POINT OF ACCOMMODATION
the nearest point at which the eye can perceive an object distinctly. It varies according to the power of accommodation
NEAR POINT OF CONVERGENCE
the nearest single point at which the two eyes can direct their visual lines, normally about three inches from the eyes in young people
NEAR VISION
ability to perceive objects clearly at normal reading distance (usually considered to be approximately fourteen inches from the eyes)
NEBULA OF CORNEA
minor opacity of the cornea
NEUROTROPHIC KERATITIS
corneal inflammation arising because of trama to the cornea
NIGHT BLINDNESS
a condition in which the sight is good by day, but deficient at night and in any faint light
NODAL POINTS
locations in an optical system toward and from which are directed corresponding incident and transmitted rays that make equal angles with the optic axis
NYSTAGMUS
an involuntary, rapid movement of the eyeball; it may be lateral, vertical, rotary, or mixed
End-position
involuntary rhythmic movement of the eyes observed when in extreme positions of gaze
Jerk
occurs with a fast and a slow pace
Labyrinthine
occurs when the labyrinths are irritated or diseased (synonym, vestibular nystagmus)
Miner's
nystagmus caused by darkness
Optokinetic
occurs in normal individuals when a succession of moving objects traverse the field of vision such as occurs when gazing out the window of a moving vehicle at a succession of stationary objects (synonym, railroad nystagmus)
Pendulous
occurs when vision in both eyes has been defective since birth
Rotary
eyeball partially rotates around the visual axis
OCULIST or OPHTHALMOLOGIST
a physician (M.D.) who specializes in diagnosis and treatment of defects and diseases of the eye, performing surgery when necessary or prescribing other types of treatment, including glasses
OCULAS DEXTER
(O.D.) right eye
OCULAS SINISTER
(O.S.) left eye
OCULUS UTERQUE
(O.U.) both eyes
OPHTHALMAIA
inflammation of the eye or conjunctiva
OPHTHALMIA NEONATORUM
an acute purulent conjunctivitis of the newborn; gonorrheal inflammation of the eyes of the newborn from the birth canal
OPHTHALMOLOGIST
a physician who specializes in diseases of the eye
OPHTHALMOPLEGIA
paralysis of the ocular muscles
External
paralysis of the external ocular muscles
Internal
paralysis of the muscles of the iris and the ciliary body
Total
combination of both intrinsic and extrinsic paralysis
OPHTHALMOSCOPE
illuminated instrument for examining the interior of the eye
Direct
provides an upright image of about 15 diameters magnification
Indirect
convex lens is held in front of the eye as an inverted image is observed; provides a magnification of about four times but allows examination of a more peripheral portion of the fundus than direct ophthalmoscopy
OPTIC ATROPHY
atrophy of the optic nerve
OPTIC CHIASM
the crossing of fibers of the optic nerves on the ventral surface of the brain.
OPTIC DISK
head of the optic nerve in the eyeball
OPTIC NERVE
the special nerve of the sense of sight which carries messages from the retina to the brain
OPTICIAN
one who grinds lenses, fits them into frames, and adjusts the frames to the wearer
OPTOMETRIST
a licensed, nonmedical practitioner (OD), specializing in vision problems, treating vision conditions with spectacles, contact lenses, low vision aids and vision therapy, and prescribing medications for certain eye diseases
ORBIT
the bone cavity containing the eye; the eye socket
ORTHOPHORIA
tendency for the eyes to be parallel, normal ocular muscle balance
ORTHOPITIC TRAINING
fusion training, series of scientifically planned exercises for developing or restoring the normal fusion teamwork of the eyes
ORTHOPTICS
technique of providing correct and efficient visual responses, usually by the form of visual training; these measures include the treatment of functional amblyopia, management of convergence insufficiency, and diagnosis of muscle imbalance and strabismus
ORTHOPTIST
one who provides orthoptic training
PALPEBRAL
pertaining to the eyelid
PANNUS
invasion of the cornea by infiltration of lymph and formation of new blood vessels
PANUM'S AREA
spatial area surrounding the horopter in which objects are viewed with stereopsis; outside this area, diplopia occurs
PAPILLA
a small elevation
Lacrimal
slight elevation on eyelid margin near the nose; particularly evident in the elderly
Optic disk
a misnomer in that the disk does not project into the eye
PAPILLEDEMA
swelling of the optic disk with engorged blood vessels, associated with elevated pressure within the skull
PAPILLITIS
inflammation of the optic disk or optic neuritis
PARTIALLY SEEING CHILD
for educational purposes, a partially seeing child is one who has a visual acuity of 20/70 or less in the better eye after the best possible correction, and who can use vision as the chief channel of learning
PERIMETER
an instrument of measuring the field of vision
PERIPHERAL VISION
ability to perceive presence, motion, or color of objects outside of the direct line of vision; the vision of the retinal outside the macula area
PHAKOMATOSES
group of hereditary diseases characterized by the presence of spots, tumors, and cysts in various parts of the body; types recognized as associated with ocular findings are tuberous sclerosis, Lindau-von Hippel disease, von Recklinghausen's disease, Bourneville's disease, and Louis-Bar disease
PHORIA
a root word denoting a latent deviation in which the eyes have a constant tendency to turn from the normal position for binocular vision; used with prefix to indicate the direction of such deviation (hyperphoria, exophoria, exophoria)
PHOTOPHOBIA
abnormal sensitivity to and discomfort from light
PHOTOPSIA
subjective sensation of sparks and flashes of light that occur in some pathologic conditions of the optic nerve, the retina, or the brain
PHTHSIS BULBI
degenerative shrinkage of the eyeball
PILOCARPINE
a drug used in ophthalmology to contract the pupil and to reduce ocular tension
PINGUECULA
a small yellowish white subconjunctival elevation composed of elastic tissue; may occur on either side of the cornea
PINK EYE / CONJUNCTIVITIS
a contagious inflammation of the conjunctiva
PITS IN OPTIC DISK
coloboma of the optic disk causing poor vision, sometimes associated with central serous chorioretinophathy
PLACIDO'S DISK
device composed of concentric black and white lines that are reflected onto the anterior surface of the cornea to detect astigmatism
PLEOPTICS
a method of treating amblyopia through the use of instruments which restore fixation to the fovea by direct stimulation or by the production and correct localization of afterimages
POLIOSIS
condition characterized by the absence of pigment in the hair; poliosis of the eyelashes occurs in sympathetic ophthalmia, syphilis, and Vogt-Koyanagi's-Harada syndrome
POLYCORIA
more than one pupil in the iris
POSTERIOR CHAMBER
space between the back of the iris and the front of the vitreous; filled with aqueous
PRESBYOPIA
a gradual lessening of the power of accommodation due to a physiological change (hardening of the lens) which becomes noticeable after the age of forty
PROSTHESIS
an artificial substitute for a missing eye (or other missing part of the body)
PROTANOMALY
form of anomalous trichromatism for which, in a red-green mixture, more than the normal amount of red is required than for normal observer
PROTANOPE
person having protanopia
PROTANOPIA
form of discoloration in which red and bluish green are confused, and relative luminosity of red is much lower than for normal observer
PSEUDO-ISOCHROMATIC CHARTS
charts with colored dots of various hues and shades indicating numbers, letters or patterns, used for testing color discrimination
PSEUDO-ISOCHROMATIC PLATE
see Ishihara color plates
PTERYGIUM
a triangular fold of growing membrane which may extend toward the cornea on white of the eye. It occurs most frequently in persons exposed to dust or wind.
PTOSIS
a paralytic drooping of the upper eyelid. See Blepharoptosis.
PUNCTA
a small opening on the inner surface of the lids at the nasal angle leading into the lacrimal duct
PUPIL
variable sized black circular opening in the center of the iris that regulates the amount of light that enters the eye
Adie's
abnormality in the reaction of the pupil to light and associated with hypotonic deep reflexes
Argyll Robertson
pupil that does not constrict to light, but constricts to accommodation; pupils are small, unequal in size, and irregular; seen mainly in tabes dorsalis
Cat's Eye
pupil with a white reflex when light is directed into it; most commonly associated with retinoblastoma
PUPILLARY MEMBRANCE
anomaly of the iris, usually minor, in which there is failure of the fetal papillary membrane to atrophy; often persistent strand extends between the iris collarette and the anterior lens capsule
PURKINJE SHIFT
luminosity curve of dark-adapted individual peaks at 500 nm. Whereas the luminosity curve of light-adapted individual peaks at 550 nm, indicates two types of retinal photoreceptors
RECTI MUSCLES
four of the extrinsic muscles of the eye, namely, the internal, external, superior, and inferior rectus muscles
RED EYE
lay term applied to any condition with dilation of conjunctival or ciliary blood vessels
REFLEX
involuntary, invariable, adaptive response to a stimulus
Accommodation
constriction of the pupils when the eyes converge for near vision; an associated reaction and not a reflex
Auditory
brief closure of the eyelids resulting from a sudden sound
Conjunctival (lid)
closure of the eyelids induced by touching the cornea (also called Corneal Reflex).
Consensual Light
constriction of the pupil when the opposite retina is stimulated with light
Direct
light contraction of the sphincter pupillae induced by stimulation of retina with light (also called Pupillary Relex)
Eyeball Compression (oculo-cardiac)
decrease of heartbeat caused by pressure on the eyeball
Fixation
involuntary eye movement that positions the eye to image a viewed object on the fovea
Foveal
tiny optical reflection from the concave mirror like surface of the foveal depression in the retina. Visible with an ophthalmoscope
Red
glow of light seen to emerge from the pupil when the interior of the eye is illuminated
REFRACTION
deviation of rays of light when passing from one transparent medium into another of a different density. The optical adjustment of the eye when in a state of rest; the ability of the eye to bring parallel ray to a sharp focus on the retina; determination of the refractive errors of the eye and their correction by glasses.
REFRACTIVE MEDIA
the transparent parts of the eye having refractive power; cornea, aqueous, lens, and vitreous
RETINA
innermost coast of the eye, formed of sensitive nerve fibers and connected with the optic nerve. Thin nerve membrane by means of which we see, being an expansion of the optic nerve. It lies between the vitreous and the choroid.
RETINAL DETACHMENT
separation of the retina from the choroid
RETINAL HOLE
break in the continuity of the neural retina so that there is a communication between the vitreous cavity and the potential space between the neural retina and the retina pigment epithelium
RETINITIS PIGMENTOSA
a hereditary degeneration and atrophy of the retina. Night blindness, usually in childhood, is followed by loss of peripheral vision progressing to tunnel vision and finally blindness
RETINOBLASTOMA
common autosomal dominant malignant retinal tumor of infancy. Probably always congenital, occurs in children, sometimes in one eye, at times in both, occasionally in successive children of same family
RETINOPATHY
a disease of the retina, due to various causes
RETINOPEXY
surgical procedure to correct retinal detachment by means of diathermy (heat) or cryo (cold)
RETINOSCHISIS
retinal abnormality in which the neural retina splits at the level of the bipolar layer
RETINOSCOPE
an instrument for determining the refractive state of the eye by observing the movements of lights and shadows across the pupil by the light thrown onto the retina from a moving mirror
RETINOSCOPY
measuring an eye's refractive error by using an retinoscope
RETROBULBAR NEURITIS
inflammation of the optic nerve occurring without involvement of the optic disk
RETROLENTAL FIBROPLASIA
Obsolete term for retinopathy of prematurity. It is characterized by prematurity and oxygen concentrations exceeding 40 percent with resultant retinal degeneration and detachment. Complications such as total retinal separation, glaucoma, and atrophy may follow.
RODS
together with cones are receptors of the optic nerve; the light perceiving layer of the retina; increase in number going from the fovea toward the periphery; are not differentially sensitive to various colors; stimulation of the rods produces only discrimination gray
sc (SIN CORRECTION)
without correction; that is, not wearing glasses
SAFETY GLASSES
impact resistant; available with or without visual correction for workshop or street wear protection, for both adults and children
SALMON PATCH
central area of intense vascularization that occurs in interstitial keratitis with the confluence of all blood vessels at the center of the cornea
SARCOMA
a malignant tumor
SATTLER'S VEIL
swelling and clouding of superficial layers of the cornea, particularly that following prolonged wearing of a contact lens
SCHIRMER'S TEST
test of tear formation in which filter paper is folder over the lid margin and the amount of wetting in 4 minutes is measured in millimeters
SCLERITIS
inflammation of the sclera
SCLEROMALACIA
softening and thinning of the; usually associated with severe rheumatoid arthritis
SCLEROSING KERATITIS
inflammation of the cornea in which it becomes white and opaque resembling the sclera
SCOTOMA
a blind or partially blind area in the visual field
SCOTOPIC ADAPTATION
adaptation to low levels of light at which only rod vision is operative
SEROUS CHORIORETINOPATHY
term applied to limited separation of the sensory layer of the retina from the pigment epithelium layer by fluid
SIDEROSIS BULBI
chronic inflammation of the eye due to a retrained iron foreign body within the eye
SLIT LAMP
see Biomicroscope. Provides a narrow slit beam of light like a searchlight, used with a binocular microscope for examination of the anterior portion of the eye.
SNELLEN CHART
a chart for testing central visual acuity, in which the letters or symbols are drawn to the Snellen Scale of Measurements, in such a away that the uppermost letter is designed to be read by the normal eye at 200 feet; rows of letters follow which should be at 100, 70, 50, 40, 30, 20, 15 and 10 feet
SNELLEN LETTER
letter so constructed that at a given distance from the eye it subtends an angle of 5 minutes, with each portion of the letter subtending an angle of 1 minute
SPHERICAL LENS
segment of sphere refracting rays of light equally in all meridians
SQUINT
cross-eyes (strabismus)
STAPHYLOMA
bulging of the eye surface that includes part of the uvea into an area of thin stretched sclera
STEREOSCOPE
an instrument for the fusion of two separate pictures in such a way as to produce a single picture having the appearance of solidity and length
STEROSCOPIC VISION
ability to perceive relative position of objects in space without such cues as shadow, size, and overlapping
STILES CRAWFORD EFFECT
light passing through the center of the pupil of the eye is more effective in evoking the sensation of brightness than the same amount of light passing through an equal area near the edge of the pupil
STRABISMUS
eye misalignment; failure of the two eyes to direct their gaze at the same object because of muscle imbalance
Comitant
deviation of the eyes in which there is no ocular muscle paralysis and the degree of crossing is the same in all directions of gaze
Noncomitant (incomitant)
degree of misalignment varies in different positions of gaze because an extraocular muscle is paretic, paralytic, or restricted
STROMA
supporting tissues of an organ
STYE
acute inflammation of the sebaceous gland in the margin of the eyelid, due to infection and usually resulting in the formation of pus. See Hordeolum
SUBCONJUNCTIVAL HERMORRAGE
bleeding beneath the neural retina and the vitreous body; a meniscus level is often present
SUBLUXATION OF LENS
condition of the lens when a portion of the supporting zonule is absent and the lens lacks support in one or more quadrants
SUPERIOR OBLIQUE MUSCLE
one of the six extrinsic muscles of the eye; it moves the eye down and out and rotates it inward
SUPERIOR RECTUS MUSCLE
one of the six extrinsic muscles of the eye; it moves it up
SUPRESSION
physiologic mental process whereby the retinal image transmitted by one eye is ignored
SYMBLEPHARON
adhesion between palpebral and bulbar conjunctiva
SYMPATHETIC OPHTHALMIA
granulomatous uveitis that follows in the opposite eye when there are penetrating injuries of one eye; the eye secondarily affected is called the sympathizing eye, while the injured eye is called the excited or activating eye
SYNECHIA
adhesion, usually of the iris to cornea or lens
SYNDROME
a group of symptoms and signs that occur together; disease of definite morbid process having a characteristic sequence of symptoms; may affect the whole body or any of its parts
Anton
form of anosognosia in which the patient denies his blindness; usually accompanied by confabulation, with the patient claiming to see objects in the blind field
Bassen-Kornzweig
progressive ataxic neuropathy associated with retinal pigmentary degeneration and a crenated appearance of erythrocytes (A-beta-lipoproteinemia)
Batten-Mayou
juvenile form of amaurotic familial idiocy with macular degeneration and optic atrophy
Behcet
chronic inflammation and vascular lesions in the mucous membranes of the mouth and genitalia. Eye findings include severe uveitis, optic neuritis, and iridocyclitis
Behr
macular degeneration seen in adult life
Benedikt
Paralysis of one eye accompanied by paralysis and tremor of the arm on other side of the body
Berlin
retinal edema following ocular contusion
Best
hereditary type of vitelliruptive macular degeneration characterized by a macular lesion having an ophthalmoscopic appearance of an egg fried "sunny side up" and associated in this stage with good vision; when egg is "scrambled," vision deteriorates
Bielschowsky-Jansky
diffuse nervous system, lesions in the macula, and optic nerve degeneration
Bowen
slow-growing, malignant tumor, commonly arising at multiple sites near the limbus (corneo-scleral junction) but limited to epithelial layer
Cavernous Sinus
thrombosis of the cavernous sinus with third, fourth, and sixth cranial nerve palsy and edema of the face and eyelids and infection
Cerebellopontine angle tumor
ataxia, tinnitus, deafness, ipsilateral paralysis of sixth and seventh cranial nerves, involvement of the fifth cranial nerve, vertigo, and nystagmus
Chiasmal
blind areas in the outer half of the visual field in both eyes
Coats
chronic progressive retinal abnormality characterized by retinal deposits and malformation of retinal blood vessels
Cogan
corneal disorder characterized by abnormal growth of blood vessels into mid-corneal layers, severe inflammation of iris and ciliary body, and deafness
Crocodile Tears
spontaneous lacrimation that occurs with the normal salivation of eating; follows facial nerve paralysis and is due to aberrant regenerating nerve fibers so that some destined for the salivary glands go the lacrimal gland
Crouzon
craniofacial dysostosis with eyes widely separated
Danlos-Ehlers
widespread systemic disorder with overextensibility of joints, hyperelasticity of the skin, fragility of the skin, and pseudotumors following trauma; there may be epicanthal folds, esotropia, blue sclera, glaucoma, ectopic lenses, and proliferating retinopathy
Devic
paraplegia and inflammation of both optic nerves, causing marked vision loss
Down's
eye signs include mongoloid slant, Brushfield spots in iris, cataracts, esotropia, myopia, blepharitis, and keratoconus
Duane's Retraction
eye muscle abnormality characterized by inability to move one eye outward past the midline and retraction of that eye into the orbit, with narrowing of the eyelid fissure on attempted movement of the at eye toward the nose
Eales
vasculitis of the retinal vessels characterized by inflammation, occlusion, neovascularization, and recurrent retinal hemorrhages, occurring particularly in young men
Familial Autonomic Dysfunction (Riley-Day)
reduced or absent tears, postural hypotension, excessive sweating, corneal anesthesia, exotropia, and absence of taste buds
Foster Kennedy
optic atrophy on the side of the lesion and papilledema on the opposite side that occur in tumors on the frontal lobe of the brain
Foville
paralysis of the limbs on one side of the body and of the face on the opposite side together with loss of power to rotate the eyes to that side
Fuchs
inflammation of the iris and ciliary body, and secondary cataract
Gaucher's
genetic deficiency of enzyme B-glucosidase. Eye signs include yellowish-brown fleshy conjunctival deposits, corneal clouding, and macular degeneration
Gradenigo
palsy of the lateral rectus muscle and severe unilateral headache in supportive disease of the middle ear
Gronblad-Strandberg
angioid streaks under the retinal due to damage in Bruch's membrane, and macular hemorrhages and scarring
Hand-Shuller-Christian
overproduction of urine, forward displacement of the eyes, and skull defects. May exhibit optic nerve swelling and an inability to move the eyes, usually before age 10
Heerfordt
uveitis, fever, and parotid gland swelling; now recognized as a manifestation of sarcoidosis
Hepato-lenticular Degeneration (Wilson)
abnormality of copper metabolism associated with progressive degeneration of the liver and lentate nucleus, mental retardation, and a brownish ring (Kayser-Fleisher) composed of copper at the periphery of the cornea.
Horner
sympathetic nerve paralysis with constricted pupil, droopy eyelid, reduced facial sweating
Hunter
metabolic dysfunction characterized by skeletal abnormalities, mental retardation and cloudy corneas, all after age 30
Hurler (gargoylism)
characterized by dwarfism with short spinal column, short fingers, depression of the bridge of the nose, heavy, stiffness of joints, cloudiness of cornea, retinal degeneration, heart problems, and mental retardation
Laurence-Moon-Biedl
inherited disturbance of the pituitary gland characterized by obesity, underdeveloped sex organs, mental retardation, extra fingers and toes, and retinal degeneration
Leber
rapidly progressive optic nerve degeneration affecting both eyes occurring about the age of 20 years
Lindau-von Hippel
characterized by tumors of the retina, central nervous system and visceral organs. Primary eye findings are blood-filled retinal tumors bed by large, vessels
Marcus Gunn
droopy eyelid that opens wide when chewing, sucking or moving mouth to the opposite side of body
Marfan's
connective tissue disease with spidery fingers and toes, relaxed ligaments, spine and joint deformities, congenital heart disease, and dislocated lenses. May be myopic and have large corneas, cataracts, and droopy eyelids, strabismus, or incomplete choroidal formation.
Niemann-Pick
fatty deposits accumulate in organs, nerve tissue, and eyes. Retinal changes may include cherry red spots or grayish haze
Orbital Apex
limitation of eye movement, bulging eye, and decreased corneal and eyelid sensation. Optic nerve involvement causes decreased vision and visual field loss
Osteogenesis Imperfecta (Van der Hoeve)
bone fragility, blue sclera, and deafness
Parinaud Oculoglandular Conjunctivitis
conjunctival lesions surrounded by follicles
Parinaud's
decreased ability to move the eyes up or down, brainstem lesion near the vertical gaze center
Purtscher
multiple retinal white patches, cotton-wool spots, hemorrhages, and swelling of the retina following sever chest trauma that causes a sudden increase in venous blood pressure
Refsum
hereditary retinal degeneration, polyneuritis, deafness, and cerebellar signs
Reiter
arthritis, urethritis, conjunctivitis, or iritis
Riley-Day
nervous system disorder with reduced tear production, decreased corneal sensation, exotropia, myopia, excessive sweating
Sjogren
connective tissue disease with dry eyes, mouth and arthritis
Stargardt
degenerative disease of the macula occurring before puberty
Stevens-Johnson
severe conjunctival disease, eye lid scarring, dry eyes, and closure of the tear ducts
Stickler's
progressive connective tissue disease that causes joint problems Mid-facial flattening, cleft palate, hearing loss, myopia, cataracts and vitreoretinal degeneration
Sturge-Weber-Dimitri
reddish pigmentation on side of face, often associated with glaucoma, large eye
Synechiae
adhesion between the iris and adjacent structures
Tay-Sachs
opaque central retina due to lipid-filled ganglion cells, fovea appears as a cherry red spot, pale optic nerve, leads to blindness and death
Vogt-Speilmeyer
diffuse nervous system disease, macular lesions, and optic nerve degeneration
Weber
paralysis of the oculomotor nerve (N III) on the same side as the lesion and spastic hemiplegia on the side opposite the lesion with increased reflexes and loss of superficial reflexes
TALBOT
unit of light equal to one lumen-second
TANGENT SCREEN
a large black or gray curtain supported by a framework on which the normal central field and blind spot have been lightly outlined. This instrument is used for measuring the central field of vision
TARSORRHAPHY
operation in which the lids are sutured together
TARSUS
the framework of connective tissue which gives shape to the eyelid
TELESCOPIC GLASSES
magnifying spectacles founded on the principles of a telescope; occasionally prescribed for improving very poor vision which cannot be helped by ordinary glasses
TEMPORAL ARTERITIS
giant cell arteritis
TENSION, INTRAOCULAR
test by means of which the amount of fluid forced from the eye by a constant pressure during a constant period is determined
TONOMETER
instrument for measuring ocular tension
Applanation
instrument used to measure intraocular pressure in which the globe is not indented
Schiotz
indentation type of instrument
TOXIC AMPLYOPIA
poor vision secondary to poisoning of any kind
TOXOPLASMOSIS
severe intraocular infection caused by the presence of toxoplasma gondu organisms; transmitted through the feces of domestic animals such as cats or birds or ingestion of raw meat containing organism
TRACHOMA
a form of infectious kerato-conjunctivitis caused by a specific virus which in the chronic form produces severe scarring of the eyelids and cornea
TRICHIASIS
condition in which eye lashes turn inward toward the eyeball
TRITANOPIA
form of dichromatism in which there are but two cone pigments present and there is a complete insensitivity to blue
TROPIA
a root word denoting a manifest deviation from normal of the axis of the eyes (strabismus) used with a prefix to denote the type (hetertropia, estropia, exotropia)
TUNNEL VISION (GUN-BARREL, TUBULAR)
contraction of the visual field to such an extent that only a small area of central visual acuity remains, thus giving the affected individual the impression of looking through a tunnel
ULCER OF THE CORNEA
a loss of substance of the surface of the cornea secondary to infection
UVEA
the iris, ciliary body, and choroid
UVEAL TRACT
entire vascular coat of the eyeball. It consists of the iris, ciliary body, and choroid.
UVEITIS
inflammation of the iris, ciliary body, and choroid
VASCULAR
of or pertaining to the blood vessels
VERNAL CONJUNCTIVITIES
inflammation of the conjunctiva presumably due to allergy and characterized by giant papillary hypertrophy of the conjunctiva
VISION
the art of seeing; sight
Binocular
using both eyes synchronously, without diplopia
Color
ability to distinguish subjectively a large variety of wavelengths of light in the visible spectrum
Photopic
vision in bright illumination
Scotopic
vision in dim illumination or vision following the biochemical or neurologic changes occurring in dark adaptation
VISUAL ACUITY
central or direct vision for distance and near; the vision record which a person attains on a chart, usually the Snellen Chart
VISUAL ANGLE
angle that an object or details subtends at the point of observation; usually measured in minutes of arc
VISUAL FIELD
full extent of the area visible to an eye when the head and eyes are kept fixed
VISUAL LINE
that line which connects a point in space with the fovea centralis
VISUAL PURPLE
a pigmentary substance in the retina reacting to light in such a manner as to produce nervous impulses which are interpreted finally as visual sensation
VITREOUS
transparent, colorless mass of soft gelatinous material filling the eyeball behind the lens
VITREOUS OPACITIES
See "FLOATERS"
XANTHELASMA FLAT
sharply circumscribed deposits of lipid in the eyelids, sometimes associated with hypercholesterolemia
YELLOW SPOT
term applied to macula lutea
ZONULE OF ZINN
the suspensory ligament of the crystalline lens