Download Parts of the Eye

1
Eye Conditions
Medical Descriptions
Glossaries
Functional and Educational Considerations
2
SECTION VIII - EYE CONDITIONS
Introduction
3
Eye Conditions
4
Achromatopsia
Albinism
Amblyopia Ex Anopsia (Lazy Eye)
Aniridia
Cataract
Chorioretinitis
Coloboma of Choroid, Iris, Retina,
Optic Nerve, Optic Disk
Corneal Scarring
Detached Retina
Diabetic Retinopathy
Dislocation of Lens
Glaucoma
Histoplasmosis
Hyperopia
Keratoconus
Leber's Congenital Amaurosis
Macular Degeneration
Marfan's Syndrome
Myopia
Nystagmus
Optic Atrophy
Retinitis Pigmentosa
Retinopathy of Prematurity (ROP
Parts of the Eye
Glossary of Eye Terms
Eye Report Terms
Cortical Visual Impairment
4
4
4-5
5
5
6
6
6-7
7
7-8
8
8
8-9
9
9
9 -10
10
10
10 - 11
11
11 - 12
12
12
13 - 14
14 – 19
19 - 20
20
3
INTRODUCTION
The Eye Conditions Section can serve as a guide to assist the teacher in understanding the medical aspects
of an eye condition and the educational implications of that condition.
Knowing a student's eye condition, its medical description and the reported visual acuity will not
necessarily indicate how the student will function visually in various settings.
A student's visual functioning can vary depending on several factors including:
eye condition
severity of condition
stability of condition
onset of condition (pre-, para-, or post natal)
A student's visual functioning may be affected in these ways:
reduced visual acuity (near and/or distant)
restricted field of vision (peripheral or central)
defective color vision
fixation problems (inability to focus on an object)
The teacher can assess a student's visual functioning by utilizing:
informal assessments
personal observations parent information student information
formal assessments
eye specialist report V medical report V/formalized assessment tests
Topics on the following pages include:
Eye Conditions
Diagram of the Eye
Parts of the Eye
Terms Relating to the Eye
Eye Report Terms
EYE CONDITIONS
The following is a partial listing of eye conditions most commonly appearing in school-age children.
Each listing includes:
name of condition
definition
functional characteristics
educational implications
4
Achromatopsia: Malformation of the cones and rods
Congenital or hereditary
Nonprogressive
Decreased visual acuity
Defective color vision
Normal visual fields
Nystagmus
Sensitive to light; dim illumination preferred
Near vision better than distant vision
Low vision aid may be prescribed
Sunglasses, shields, visors, tinted lenses for light sensitivity
Yellow acetate over print to improve contrast
Cut out window to expose only one word at a time to improve fixation
Black felt pen for marking and writing
Albinism: Lack of pigment; inability of the body to produce pigment; may involve all pigmented
structures (complete) resulting in fair complexion, platinum blonde hair and light-colored eyebrows; may
be incomplete and involve only certain structures such as the eye (ocular albinism)
Congenital or hereditary
Nonprogressive
Decreased visual acuity
Visual fields usually normal
Nystagmus
Neat-sighted or farsighted
Sensitive to light; dim illumination preferred
Contact lenses often prescribed
Acuity often improved with glasses
Sunglasses, shields, visors, tinted lenses for light sensitivity
Yellow acetate over print to improve contrast
Black felt pen for marking and writing
Large print materials may be required
Problems in self-concept (especially in adolescence and among black children) because of albinism
Glare from all surfaces avoided (windows, chalkboards, desks, papers)
Amblyopia Ex Anopsia (Lazy Eye): Focusing of visual images upon the retina is suppressed.
Adventitious
Progressive
Central field loss
Decreased visual acuity
Average light preferred
Depth perception problems
Exercise of such an eye before the seventh year (unaffected eye occluded) frequently will improve the
visual acuity
5
Double vision when eye is not patched
Temporary adjustments during patching (the child may function as a visually impaired student and be
eligible for special services as long as the patching continues)
Black felt pen for writing and marking
Yellow acetate over print to improve contrast
Aniridia: Failure of the iris to develop fully
Congenital or hereditary
Progressive
Decreased visual acuity
Usually bilateral
Nystagmus
Extreme light sensitivity; average or dim illumination preferred
Further complication with glaucoma, resulting in restricted fields and cloudiness of the cornea
Associated defects: cataracts, displaced lens, and underdevelopment of the retina
May indicate presence of Wilm's tumor in children under two years old
If glaucoma, restricted fields; pain from pressure
Medication may be prescribed
Physical activity ma y be restricted; consult student's physician
Cataract: Any opacification (cloudiness) of the lens
Congenital or adventitious
Progressive or nonprogressive
Visual fields usually normal
Nystagmus in severe cases
Blurred vision
Variable vision due to size, position, and density of opacity
Central or posterior cataracts - sensitivity to bright light
Cortical cataracts - poor color discrimination
Surgery may be necessary in cases of severe visual impairment
Removal of congenital cataracts often results in formation of secondary cataracts; improved surgical
techniques result in fewer complications
After surgery, need aphakic correction (usually contact lens; experience greater sensitivity
to glare)
Average or dim light
Medication may be prescribed
Physical activity may be restricted; consult student's physician
Magnification of materials and/or large print
Stand magnifiers or hand-held magnifiers
Black felt pen for marking and writing
Special lens prescribed for glasses (e.g., one for reading, another for travel)
Good contrast in books and on board (white chalk on blackboard, rather than a green board)
Glare from all surfaces avoided (windows, chalkboards, desks, papers)
Sunglasses, shield, visors for light sensitivity
Expose only one word at a time to improve fixation while reading
6
Chorioretinitis: Inflammation of the retina and choroid causing seepage from the blood vessels to
accumulate on the retina and sometimes the cornea.
Adventitious
Progressive or nonprogressive
Peripheral or central field loss
Loss of vision as areas of the retina are damaged by the infection
Gradual blurring of vision
Eye may appear red
Sensitive to light
Peripheral field loss; may have trouble traveling in crowded hallway or playground
Magnification of materials and/or large print
Damage in central part of retina
Medication may be prescribed
Independent travel training (Orientation and Mobility) may be necessary
Glasses may or may not be beneficial
Coloboma of choroid, iris, retina, optic nerve, or optic disk: Usually absence of the choroid in the
lower part of the eye and a keyhole-shaped pupil rather than the normal round opening.
Congenital or hereditary
Nonprogressive
Peripheral field loss
Variable central acuity
Iris, choroid, or other parts of the eye may be effected
Visual acuity ranges from near normal to very poor, depending on the number of structures involved
Blind spot enlarged
Visual field defect
Average or bright light
Glasses and/or hand-held magnifiers
Central vision allows use of monocular lens for distance; distant vision training may be
needed.
Large print or braille
Depth perception may be affected, especially in lower fields, causing problems in physical education
Typing will ease writing problems
Book stands may aid in reading materials
Markers, dark-lined paper, instruction on using margins (folding paper for columns, lattice form for math
problems, one-half sheets for spelling tests) may be necessary
Taped lessons alternated with reading activities
Corneal Scarring: Scarring of the cornea due to trauma, infection, or corrosives.
Adventitious
Nonprogressive
Astigmatism
Keratoplasty (corneal graft) may be beneficial
Postinfectious scars may clear spontaneously with time
7
Bright or average light
Contact lenses may improve vision
Glasses may be prescribed
Standard print, large print, magnification, or braille depending on scars present
Unusual head positions may be required for reading
Detached Retina: Separation of the retina and the choroid layer; separation breaks connections between
cones and rods and the pigment layer; pathological myopia and accumulation of fluid under the retina are
major causes.
Adventitious
Progressive and nonprogressive
Varying visual field losses
Hole or tear in retina probable
Surgery required immediately in most cases
Surgery may or may not restore vision depending upon etiology of detachment, treatment methods, and
duration of a successful result
Surgery may accelerate cataract changes
Near vision often corrected earlier than distant vision following surgery
Recovery often slow and requires months to reach best level of improvement
Children frequently recover good visual acuity
Double vision may follow surgery
Periodic eye exams are important
Correction may be prescribed (may change two to three times during first six months after surgery)
Warning signs:
Flash of light in the side vision
Multiple spots and particles floating in the space in front of vision
Color vision impaired
Mycropsia objects appear smaller
Persons who have predisposition to detached retina may consider avoiding contact sports and other sports
(danger of blows to head and eyes); consult with student's physician
Unusual head positions may be required for reading,
Magnification and/or large print
Diabetic Retinopathy: Changes in the blood vessels of the retina causing hemorrhaging
Adventitious
Progressive
Central field loss
Color vision loss
Variable visual field loss
Variable acuity
Retinal detachment may occur
Bright or average light preferred
Possible sudden loss of Vision
Glaucoma may develop
8
Clip-on high power loupe (special lens) may be useful
Stand magnifiers and hand-held magnifiers
Binocular half-eye prism glasses for background retinopathy
Medication may be prescribed
Physical activity may be restricted; consult student's physician
Dislocation of Lens: Displacement of the lens; usually associated with trauma or with certain hereditary
syndromes such as Marfan's syndrome
Congenital or hereditary
Nonprogressive
Average or dim light preferred
Visual impairment may be corrected by dilating the pupils; enables student to look around the dislocated
lens
Aphakic glasses (often prescribed after cataract surgery)
Dislocated lens may be removed
Myopic correction may be prescribed
Magnification of materials
Large print may be beneficial
Medication may be prescribed
Physical activity may be restricted; consult student's physician
Glaucoma: Increased intraocular pressure of the eye; types of glaucoma: primary, congenital, or
secondary glaucoma
Congenital or adventitious
Progressive or nonprogressive
Peripheral field loss
Defective night vision
Decreased visual acuity
Bright, average, or dim light
Surgical procedures and drugs used to control pressure
Anxiety over ocular pressure (''is it up again?" "Did you forget your drops?") contributes to difficult
emotional adjustments in children
Large print or braille
Black felt pen for marking or writing
Long reading sessions should be avoided (intersperse activities which do not require close work)
Glare from all surfaces avoided (windows, chalkboards, desks, papers)
Sunglasses, shields, visors for light sensitivity
Variable acuity; may require variety of materials and tasks
Dark lined paper
Histoplasmosis: Infection due to a yeast-like fungus organism; caused by inhalation or ingestion of spores
of the organism (found in soil or dried excrement of animals)
Congenital or adventitious
Nonprogressive
Color vision loss
9
Scattered areas of inflammation (lesions) in the back of eye
Macular area infection; greatly reduced visual acuity and central visual area
Squint may develop
Telescopes/microscopes may be beneficial
Orientation and Mobility training may be necessary
Hyperopia: Farsightedness
Congenital or adventitious
Progressive or nonprogressive
Visual acuity loss
Accommodation (ability to focus) presents problems; may attempt to correct by bringing objects close to
the face, thus appearing to be very nearsighted
Glasses may be prescribed
Fatigue and other complaints of eyestrain (headache, dimness of vision) may be common,
Long reading sessions should be avoided (intersperse activities which do not require close work)
Black felt pen for marking or wr7ting
Auditory exercises - tapes, readers
Concrete -manipulation of objects in tasks rather than close Paper work
Print size and focal length determined by student's needs
Dark-lined paper
Keratoconus: Cone-shaped deformity of the cornea; other complications include retinitis pigmentosa,
Down's syndrome, Marfan's syndrome, Aniridia
Congenital or hereditary
Progressive
Variable visual acuity's
Evident in teen years
Bilateral with high astigmatism
Progressive decrease in visual acuity
Overall blurring of entire field without field loss
Distant vision distorted
Corneal transplants may be successful in severe cases
Difficulty in seeing distant objects
Contact lens correction preferable (soft lenses with over refraction for high cylindrical corrections)
New prescription every six months to a year during progression of disease
Distance glass or aid
High-plus reading spectacle
Physical activity may be restricted; consult student's physician
Leber's Congenital Amaurosis: Degeneration of the macula
Congenital or hereditary
Proqressive
Abnormal cornea and cataracts often present
Poor visual acuity
Excessive rubbing of the eyes is a characteristic behavior (produces the sensation of light
10
in front of the eyes)
Vision stimulation activities may be beneficial
Braille materials
Macular Degeneration: Degeneration of the central part of the retina
Juvenile: Congenital or hereditary; progressive
Senile: Adventitious; progressive or nonprogressive
Central field loss
Color vision loss
Average or dim light
Bifocals may be prescribed
Monocular telescopes
Sunglasses, shields, visors for light sensitivity
Small desk lights for high illumination
Closed circuit television (Apollo, Visualtek, Pelco) can be helpful
Large print may be necessary
Hand-held magnifiers
Unusual head positions may be required for reading
Marfan's Syndrome: Condition characterized by abnormally long and slender fingers, toes, and other
bones of the body; congenital heart disease, general muscular underdevelopment, high arched palate, decrease in
subcutaneous fat, and prominent ears may occur
Congenital or hereditary
Nonprogressive or progressive
Dislocated lens
General blurring of vision and double vision
Poor distant acuity
Inability to focus on visual details
Average or dim light
Mobility may be hampered by the physical condition; orientation and mobility may be beneficial
Reading glasses
Physical activity may be restricted; consult student's physician
Medication may be prescribed
Experimentation may be necessary in order to find the best working position
Frequent school absence due to the many associated problems; support and understanding required
Myopia: Nearsightedness
Congenital or adventitious
Progressive or nonprogressive
Peripheral field loss
Central field loss
Night vision loss
Problems with distant vision in classroom and gym
Glasses may be prescribed
Glasses may be thick (encourage student to wear them)
11
Telescopes
Student may be given master copy for board work
Student may be seated close for board work
Reader assistance may be necessary
Concrete materials and tactile maps used as often as possible
Desk easels for positioning books and papers
Good contrast in books and on board (white chalk on blackboard rather than green board)
Verbal cues are important
Participation in sports and some games may be restricted (possibility of detached retina in a severely
myopic student); consult student's physician
Nystagmus: Involuntary movement of the eyes
Congenital or hereditary
Nonprogressive
Stress may affect acuity and rapidity of eye movements
Eye fatigue may occur by the end of the day
Regular print or large print
Magnifiers may not always be helpful
Materials with few distractions on the page and good, clean print
Line markers/rulers to help keep place
Expose only one word at a time to improve fixation while reading
Good comprehension and language skills aid in anticipating what is coming in the sentence, even if word
skipping occurs
Reversal problems; discrimination exercises will help teach patterns
Handwriting may be a problem; the student should learn to type
Copying should be minimized whenever possible
Short assignments to prevent stress
Directions and special words should be underlined
Long reading sessions should be avoided (intersperse activities which do not require close
work)
Optic Atrophy: Degeneration of the nerve tissue which carries messages from the retina to the brain
Congenital or adventitious
Progressive or nonprogressive
Peripheral field loss
Central field loss
Night vision loss
Bright or average light
Magnification
Large print or braille
Physical activity may be restricted; consult student's physician
Glare from all surfaces should be avoided (windows, chalkboards, desks, papers)
Good contrast in books and on board (white chalk on blackboard rather than green board)
Magnifiers may be helpful if central vision is present
Glasses may-be prescribed
12
Long reading sessions should be avoided (intersperse activities which do not require close work)
Dark-lined paper
Black felt pen for marking and writing
Retinitis Pigmentosa: Migration of pigment into the retina causing loss of visual acuity
Congenital or hereditary
Progressive
Bilateral
Night vision loss
Constriction of peripheral fields
Blurred vision
0ptic atrophy
Night blindness is the first symptom
Good lighting; needs high illumination
Black felt pen for marking or writing
Dark lined paper
Yellow acetate over print to improve contrast
Reader assistance for board work
Student may appear to be looking at things sideways; central vision and vision on one side may be gone
Closed circuit television and magnifiers for student with good central vision
Large print or braille
Retinopathy of Prematurity (ROP): Mass of scar tissue that forms in the back of the lens; resulting from
excessive oxygen given to a premature infant
Adventitious
Nonprogressive
Peripheral field loss
Central field loss
Average or bright light
Myopia, strabismus, and/or nystagmus may be present
Eyes may be enucleated (surgically removed) and prostheses inserted
Perceptual problems may be present
Orientation and Mobility training may be necessary
Motor skills may be poor
Glasses may be prescribed
Telescope and closed circuit television may be helpful
Note: Persons who have
predisposition to
detached retina may
consider avoiding
contact sports and other
sports (danger of blows
to head and eyes);
consult with student's
physician
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
Congenital or adventitious
Progressive or nonprogresive
Generally not progressive but new lesions may develop
Field defects
Decreased visual acuity
13
Lesions correspond to blind areas in visual field
Usually affects the central nervous system and eyes
May cause severe brain damage
Ocular involvement more common with-congenital cases
Affected eye may squint (turning in or out of an eye)
Microscopes for near vision
Telescopes for distant viewing
Periodic exams recommended
Parts of the Eye
Anterior Chamber: Space in front portion of the eye between the cornea and iris filled with aqueous
humor
Aqueous Humor: Clear, watery fluid which fills the anterior and posterior chambers within the front part
of the eye
Bulbar Conjunctiva: Part of the conjunctiva covering the anterior surface f the eyeball
Canal of Schlemm: Circular canal situated at the juncture of the sclera and cornea through which the
aqueous humor is excreted after it has circulated between the lens, the iris, and the cornea
Canthus: The inner and outer corners of the eye where the upper and lower eyelids meet
Choroid: The vascular, intermediate layer which furnishes nourishment to the other parts of the eye,
especially the iris
Cilia: Eyelashes
Ciliary Body: A ring of tissue between the iris and the choroid consisting of muscles and blood vessels
that changes the shape of the lens and manufactures aqueous humor
Cones: Short sensory receptors in the retina that function in color vision
Conjunctiva Mucous: membrane which lines the eyelids and covers the front part of the eyeball
Cornea: The curved transparent covering on the front of the eye; a refractive surface through which light
enters
Crystalline Lens: A transparent, colorless body suspended in the eyeball, between the aqueous humor
and the vitreous humor, which brings the rays of light to focus on the retina
Extrinsic Muscles: The six external muscles which cause movement of each eye up, down, sideways, and
around
Fovea: A small depressed area of the retina composed of cones and responsible for central vision and
color vision; the most light sensitive part of the eye
Fundus: The back of the eye which can be seen with an opthalmoscope
Iris: Colored circular membrane suspended behind the cornea and immediately in front of the lens;
regulates the amount of light entering the eye by changing the size of the pupil
Lacrimal Gland: Gland located just above the outer corner of each eye that secretes tears
Lacrimal Sac: The upper end of the lacrimal duct Limbus Boundary between the cornea and the sclera
Macula Lutea: Rodfree area of the retina that surrounds the fovea and is responsible for clearest central
vision Optic Disk: Head of the optic nerve; formed by the meeting of all retinal nerve fibers at the
retina
Optic Nerve: The nerve which carries messages from the retina to the brain
Posterior Chambers: Space between the back of the iris and the front of the crystalline lens; filled with
aqueous humor
14
Pterygium: A triangular fold of growing membrane which may extend toward the cornea on the white of
the eye; occurs most frequently in persons exposed to dust or wind
Pupil: The opening in the center of the iris which appears as a black dot and through which light enters
the eye
Retina: Inner transparent membrane of light-sensitive nerve tissue connected with the brain through the
optic nerve; receives images and sends them to the brain
Rods: Light-sensitive nerve endings at the edge of the retina responsive to faint light; used in travel
vision.
Sclera: The white opaque fibrous outer covering of the eye
Uvea: The layer of the eye consisting of the iris, ciliary body, and choroid
Vitreous Humor: Transparent colorless mass of soft gelatinous material filling the globe of the eye
between the lens and the retina
Zonule: The numerous fine tissue strands which hold the lens in place
Glossary of Eye Terms
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
Adventitious: Acquired after birth
Amblyopia (Lazy Eye: Blurred vision due to disuse of the eye; no organic defect present; usually
uncorrectable after age seven
Ametropia: Refractive error, such as myopia and astigmatism, in which the eye at rest does not focus the
image upon the retina
Aniseikonia: A condition in which the image seen by one eye differs in size or shape from that seen by
the other
Anisometropia: Difference in refractive error of the eyes, e.g. one eye farsighted and the other
nearsighted
Anophthalmos: Absence of a true eyeball
Aphakia: Absence of the lens of the eye
Applanation Tonometer: Freestanding instrument which measures intraocular pressure by brief contact
with the cornea; does not require indentation of the cornea
Asthenopia: Eye fatigue caused by tiring of the internal and external muscles
Astigmatism: Defect of the curvature of the cornea or lens resulting in a distorted image; light rays cannot
focus on a single point of the retina
Atropine: Drug which dilates pupil, increases frequency of heart's action, and inhibits sweating and
salivation
Binocular Vision: Coordinated use of the eyes to focus on one object and to fuse the two images into one
Blepharitis: inflammation of the eyelids
Blind Spot: Technically, the point in the retina where the optic nerve enters and is insensitive to light
Buphthalmos: Large eyeball in infantile glaucoma
Central Visual Field: Portion of the visual field seen without moving the head or eyes
Chalazion: Inflammatory enlargement of a gland in the eyelid due to retention of its secretion
Choked Disk: Non-inflammatory swelling of the optic nerve head
Chorioretinitis: Inflammation of the choroid and retina
Choroidcremia: Absence of the choroid, the thin, dark-brown, vascular coat of the eye between the sclera
15
and the retina
Choroiditis: Inflammation of the choroid
Color Blindness: Diminished ability to perceive differences in color
Concave Lens: Lens having the power to diverge rays of light; also known as diverging, reducing,
negative, myopia, or minus lens; denoted by the sign (-)
Cones: Layer of the retina which acts as light-receiving media; cones are important for visual acuity and
color discrimination
CongenitaI: Present at birth
Conjunctivitis: Inflammation of the mucous membrane lining the eyelids and covering the inside of the
Eye
Contact Lens: Thin shell of plastic which rests directly on the tear film of the cornea and corrects
refractive errors or acts as a bandage releasing medication
Convergence: Turning of the two eyes inward toward the nose at the same time to see a nearby object
Convex Lens: Lens having the power to converge rays of light and bring them to a focus; also known as
converging, magnifying, hyperopic, or plus lens; denoted by the sign (+)
Corneal Graft: Graft Operation to restore vision by replacing a section of opaque cornea with transparent
cornea
Cover Test: Test covering one eye with an opaque object to determine the presence and degree of
deviation of the eyes from normal position
Cyclitis: Inflammation of the ciliary body
Cylindrical Lens: Lens used in the correction of astigmatism
Dacryocystitis: Inflammation of the lacrimal sac
Dark Adaptation: The ability of the retina and pupil to adjust to a dim light
Degeneration: Tissue change which lessens the ability to perform a function
Depth Perception: The ability to perceive the solidity of objects and their relative position in space
Diopter: Metric unit used to denote the strength of the eye or lens; indicated by the sign of a triangle
Diplopia: Double vision
Distant Vision: Ability to distinctly perceive objects at a distance, usually 20 feet or greater
Divergence: Turning outward of both eyes at the same time
Ectropion: Turning inside out of the eyelid
Edema: Abnormal and excessive accumulation of fluid in the spaces between tissue cells
Electroretinogram: A graphic record of electrical activity of the retina; used for the diagnosis of retinal
Disease
Emmetropia: Normal refractive state with images focused on the retina
Endophthalmitis: Inflammation of most of the internal structures of the eye
Esotropic: A turning inward of the eyelid
"E" Test: A system of testing the visual acuity of nonreaders
Exenteration: Removal of the entire contents of the orbit, including the eyeball and lids
Exophoria A tendency of the eyes to turn outward
Exophthalmos: Abnormal protrusion of the eyeball
Extropia: Obvious outward turning of one or both eyes
Exudates: Fluid or cells which escape from diseased blood vessels
Eye Dominance: Tendency of one eye to assume the major function of seeing
Far Sightedness: A refractive error in which the focal point for light rays is behind the-retina (hyperopia,
hypermetropia); the ability to see objects at a great distance
Field of Vision: The entire area which can be seen without shifting the gaze
Fixation: Directing the eye to an object so that its image, in the normal eye, centers on the fovea
Floaters: Small dark particles in the vitreous humor
16
Fluorescein Angiography: Photography of the ocular fundus after the injection of fluorescein dye into
The bloodstream
Focus: The point at which light rays meet after passing through the lenses; in normal eyes this point is on
the fovea of the retina
Fusion: The coordination of the separate images in the two eyes into a single mental image
Genetics: The study of the traits and variation of organisms and how they determine the constitution of
an individual
Glioma: Malignant tumor of the retina
Gonioscope: A magnifying device used to examine the angle of the anterior chamber
Hemianopsia: Loss of half the peripheral field of vision appearing in, or characteristic of, successive
generations; individual differences in human beings passed from parent to offspring
Herpes Simplex Keratitis: Cold sores on the cornea which cause scarring and decrease vision
Heterophoria: Constant tendency of the eyes to deviate from the normal position
Heterotropia: An obvious deviation of the alignment of the eyes; crossed eyes, strabismus
Hippus: Spontaneous rhythmic movements of the iris; iridokinesia
Hyperopia: Farsightedness; a condition in which visual images come to a focus behind the retina of the
eye and vision is better for distant than near objects
Hyperphoria: A latent tendency for one eye to deviate upward
Hypertropia: An obvious upward turning of one of the eyes.
Injection: A term sometimes used to mean congestion of ciliary or conjunctival blood vessels, redness of
the eye
Interstitial Keratitis: Infection of the middle layer of the cornea; disease found chiefly in children and
young adults; usually caused by transmission of syphilis from mother to unborn child
Intraocular Pressure: The pressure of the fluid (aqueous humor) within the eye
Iridectomy: Surgical removal of part of the iris
Iridocyclitis: Inflammation of the iris and the ciliary body
Iritis: Inflammation of the iris often accompanied by pain, discomfort from light, contraction of the pupil,
and discoloration
Ishihara Color Plates: A test for color vision based on the ability to trace patterns in a series of
multicolored charts
Jaeger Test: A test for near vision using various type sizes
Keratitis: Inflammation of the cornea accompanied by loss of transparency and dullness
Keratoplasty: See Corneal Graft
Lacrimation: Production and release of tears
Lagophthalmos: A condition in which the lids cannot be completely closed
Laser: Surgical tool using an intense beam of light energy to weld rips and holes or to destroy new blood
vessels (photocoagulation) in the eye
Legal Blindness: Central visual acuity of 20/200 or less in the better eye with correcting lenses or a
Peripheral field so contracted that the widest diameter of such field subtends an angular distance
no greater than 20 degrees
Lens: A refractive medium having one or both surfaces curved; used to improve vision
Light Adaptation: Power of the eye to adjust to variationc, in amounts of light
Light Perception: Ability to distinguish light from dark
Low Vision: Vision that can not be corrected to normal with conventional glasses
Low Vision Aids: Optical device prescribed foi visually impaired persons
Macrophthalmos: Abnormally large eyeball, resulting chiefly from infantile glaucoma
Megalocornea: Abnormally large cornea present at birth
17
Megalophthalmos: Abnormally large eyeball present at birth
Microphthalmos: Abnormally small eyeball present at birth
Microscopic Glasses: Magnifying lenses designed on the principle of a microscope, occasionally
prescribed for persons with very poor vision
Miotic: A drug that causes the pupil to contract
Mydriatic: A drug that dilates the pupil
Myopia: Nearsightedness; a condition in which visual images focus in front of the retina resulting in
Defective distant vision
Nasolacryinal Duct Stenosis: Narrowing of the tear ducts that lead to the nose
Near Point Accommodation: The nearest point at which the eye can perceive an object distinctly; varies
according to the power of accommodation
Near Point of Convergence: The nearest single point at which two eyes can focus, normally about 3
inches from the eyes in young people
Nearsightedness: A refractive error in which the focal point for light rays is in front of the retina
(myopia); the ability to see near objects better than distant objects
Near Vision: The ability to distinctly perceive objects at normal reading distance (about 14 inches from
the eye)
Night Blindness: Condition in which sight is good by day but deficient at night and/o.r any faint light
Noncontact Tonometer: Freestanding instrument used in glaucoma screening which registers intraocular
pressure electronically without direct contact with the eye; ejects a brief puff of air to the eye
which registers as a numerical value of intraocular pressure
Nonprogressive: Does not increase in extent or severity
Nystagmus: An involuntary rapid movement of the eyeball; it may be lateral, vertical, rotary or mixed
Occlusion: Obscuring the vision of one eye to force the use of the other eye (e.g., with eye patch)
Oculist or A physician (M.D.): who specializes in diagnosis or Ophthalmologist treatment of defects and
diseases of the eye, performs surgery when necessary and/or prescribes other types of treatment
including glasses, medicine and therapy
Ophthalmia: Inflammation of the eye or the conjunctiva
Ophthalmia Neonatorum: Blinding eye disease (acute inflammation) of newborn infants; often a
gonorrheal infection acquired in the birth canal from the mother
Ophthalmoscope: An instrument used in examining the interior of the eye; funduscope
Ophthalmoplegia: Paralysis of the eye muscles
Optic Atrophy: Degeneration of the nerve tissue carrying messages from the retina to the brain
Optic Chiasm: The crossing of the fibers of the optic nerve on the lower surface of the brain
Optician: Specialist who fits, adjusts, and dispenses glasses and other optical devices according to the
written prescription of a licensed physician or optometrist
Optic Neuritis: Inflammation of the optic nerve
Optics: Science of light and vision
Optometrist: A licensed, nonmedical practitioner who examines the eyes and related structures to
determine vision problems, eye disease, or other abnormalities; prescribes glasses, prisms, and
exercises.
Orthoptic Training: Series of scientifically planned exercises for developing or restoring the normal
teamwork of the eyes
Orthoptist: One who provides orthoptic training
Oscillipsia: The subjective illusion of movement of objects that occurs with some types of nystagmus
Palpebral: Fissure A cleft or groove in the eyelid
Pannus: Growth of new blood vessels and tissue deposits on the cornea
Panophthalmitls: Inflammation of all the structures and tissues of the eye
18
Perimeter: An Instrument for measuring the field of vision
Peripheral Vision: The ability to perceive object outside the direct line of vision; side vision
Phacoemulsification: A technique of cataract removal in which an instrument breaks the lens into small
particles and sucks them through a very small incision in the eye
Phlycternular Keratitis: A type of corneal inflammation characterized by the formation of pustules or
papules on the cornea; usually occurs in young children and may be caused by poor nutrition
Phoria: Any tendency for deviation of the eyes to turn away from normal
Photophobia: Abnormal sensitivity to liqht
Phthisis Bulbi: Shrunken, sightless eyeball
Pink Eye: Inflammation of the conjunctiva
Pleoptics: Exercise technique designed to develop fuller vision and binocular cooperation; a method for
treating amblyopia
Presbyopia: A gradual lessening of the power of accommodation due to a physiological change which
becomes noticeable with advanced age
Progressive: Increasing in extent or severity
Prosthesis: Artificial substitute for a missing body part such as the eye
Pseudoisochromatic Charts: Charts with colored dots of various hues and shades indicating numbers,
letters or patterns; used for testing color discrimination
Ptosis: A paralytic drooping of the upper eyelid
Red Eye: Nonmedical, term used to indicate inflammation of the eye
Refraction: As used by eye specialists, the measurement of the eye to determine refractive errors and the
need for prescription glasses; deviation in the course of the rays of light in passing from one
transparent medium into another of different density
Refractive Error: A defect in the eye that prevents light rays from focusing accurately on the retina
Refractive Media: The transparent parts of the eye having deflective power; cornea, aqueous humor, lens,
vitreous humor
Retinal Aplasia: Failure of the retina to develop into functioning tissue, with subsequent-secondary
degenerative changes
Retinal Detachment: A separation of the retina from the choroid
Retinal Dystrophy: A disorder of the retina arising from defective or fauIty nutrition
Retinitis: Inflammation of the retina
Retinablastoma: The most common malignant intraocular tumor of childhood; usually congenital
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
Rhodopsin: Visual purple; light sensitive pigment in the rod cells of the retina; important for vision in
dim light
Rods: Layer of the retina which acts as light-receiving media; rods are important for motion and vision
at low degrees of illumination (night vision)
Safety Glasses: Impact-resistant glasses for eye protection
Schiotz Tonometer: Handheld instrument which measures intraocular pressure by direct contact of a
small plunger with the cornea recording the amount of indentation
Scleritis: Inflammation of the sclera
Scotoma: A blind or partially blind area in the visual field
Slit-Lamp Microscope: A combination light and microscope for examination of the eye; principally the
anterior segment
Snellen Chart: Used for testing central visual acuity; consists of lines of letters, numbers, or symbols in
graded sizes drawn to Snellen measurements; labeled with the distance at which it can be read by
the normal eye at (20 ft.)
19
Spherical Lens: Refracts light rays equally at all points along the curved surface
Staphyloma: Protrusion of the cornea or sclera resulting from inflammation
Stereopsis: Ability to perceive relative position of objects in space without such cues as shadow, size, or
overlapping
Strabismus: Crossed eyes; failure of the two eyes simultaneously to direct their gaze at the same object;
due to muscle imbalance
Strephasymbolia: A disorder of perception in which objects seem reversed as in a mirror; a reading
difficulty inconsistent with the child's general intelligence beginning with confusion between
similar, but oppositely oriented letter (b-d, q-p) and a tendency to reverse direction in reading
Sty: Horseolum; inflammation of one or more of the sebaceous glands of the eyelids; produces pus;
usually due to infection
Sympathetic Ophthalmitis: Inflammation of one eye due to an infection of the other eye
Synechia: Adhesion usually of the iris to the cornea or lens
Target Screen: Device used to measure the central visual field using a black screen with small test
objects moving within an area corresponding to the area of central vision; plots field restrictions
Telescopic Glasses: Magnifying spectacles designed on the principles of the telescope; occasionally
prescribed for improving very poor vision which cannot be helped by ordinary glasses
Tonography: Recording changes in intraocular pressure produced by t he application of a known weight
on the globe of the eye and measurement of the rate of outflow of aqueous humor
Tonometer: An instrument for measuring intraocular pressure
Toxic Amblyopia: Dimness of vision without organic lesion of the eye due to poisoning such as tobacco
or alcohol
Trachoma: A chronic, contagious, viral infection of the conjunctiva of varying degrees of severity; can
produce scarring of eyelids and cornea
Trichiases: A turning inward of the eyelashes often causing irritation of the eyeball
Tropia: Suffix that indicates obvious deviation of the eyes from normal position for binocular vision
Tunnel Vision: Visual field contracted to give impression of looking through a tunnel
Uveitis: Inflammation of the uveal tract of the eye
Vision: The art or faculty of seeing; sight
Visual Acuity: Ability of the eye to perceive objects in the direct line of vision
Visual Efficiency: Maximal use of vision; a skill that needs to be developed with low vision students
Visual Memory: Remembering a visual image that is no longer present
Visual Motor: Coordination of sight with other functions of the body
Visual Perception: The ability to distinguish visual characteristics and to give them meaning
Eye Report Terms
C, cc :
CF:
CVF:
D:
HM:
IOP:
With correction; wearing prescribed lenses with glasses
Count fingers; low visual acuity; used in conjunction with distance; e.g., CF at 1 foot (the
individual can count fingers at a distance of one foot)
Central visual field
Diopter; lens strength
Hand movements; used in conjunction with distance; e.g., HM at I foot; the individual can
see hand movements at one foot)
Intraocular pressure; the pressure of aqueous humor within the eye
20
JI, J2, J3:
LP:
LPP:
NLP:
OD:
OS:
OU:
PLL:
SS or S, SC:
20/20 Vision:
VA:
VE:
Jaeger notation indicating the size of type which can be read
Light perception; ability to distinguish light from dark
Light projection; the ability to perceive and localize Iight
No light perception; inability to distinguish light from dark
Right eye; oculus dexter
Left eye; oculus sinister
Both eyes together; oculi unitas
Perceives and localizes light in one or more quadrants
Without correction; not wearing glasses
Normal visual acuity; ability to correctly perceive an object or letter of a designated size
from a distance of 20 feet 20/70 Visual acuity notation; ability to see at 20 feet what others
with normal acuity are able to see at 70 feet; visually impaired 20/200 Visual acuity
notation; ability to see at 20 feet what others with normal acuity are able to see at 200 feet;
legally blind
Visual acuity
Visual efficiency
Cortical Visual Impairment : Neurological condition that prevents the brain from producing the
correct visual picture from input.
Congential or acquired
No special accommodation for lighting
No special accommodation for seating
Can have 20/20 vision, but…
Physical activity should not be limited.
21