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Transcript
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