Eye Glossary

Adie’s Pupil – a pupil that does not react normally to bright light due to impaired nerve function; usually does not interfere substantially with vision

Amaurosis Fugax – temporary loss of vision in one eye; may be a sign of a transient ischemic attack (TIA) or an impending stroke

Amblyopia – the inability of an eye to see normally due to lack of input from the eye to the brain during childhood; also termed “lazy eye”

Aphakia – the absence of the eye’s natural lens, usually after cataract surgery

Arcus Senilis – a hazy ring at the edge of the cornea where the iris meets the white of the eye; does not impair vision

Bell’s Palsy – paralysis of the muscles on one side of the face due to nerve damage; usually temporary, but can interfere with blinking and protection of the eye

Blepharitis – inflammation of the eyelid; can cause irritation, discharge and even blurred vision

Chalazion – a bump in the eyelid caused by a clogged oil gland; may require surgical removal

Conjunctivitis – inflammation or infection of the conjunctiva, the mucous membrane covering the white of the eye

Corneal Edema – swelling of the cornea, often causing blurred vision

Corneal Erosion – spontaneous loss of a part of the surface “skin” of the eye-causes pain, light sensitivity and occasionally blurriness, and often occurs on awakening

Corneal Ulcer – a localized inflammation or infection of the cornea extending beneath the surface layer-must be treated immediately to prevent permanent damage

Central Retinal Artery Occlusion – blockage of the main blood supply to the eye often; causes blindness

Central Retinal Vein Occlusion – blockage of the main vein transporting blood away from the retina; causes hemorrhage in the retina and usually results in permanent vision impairment

Central Serous Retinopathy – spontaneous leakage of fluid into the retina, often in young, healthy people – cause is unknown

Dacryocystitis – infection in the tear sac adjacent to the nose-causes pain, swelling, tenderness and tearing

Dermatochalasis – excess or baggy skin on the eyelids, usually from loss of elastic tissue in the skin

Diplopia – double vision; usually caused by misaligned eyes

Drusen – discolored spots in the retina – can be an early sign of macular degeneration

Ectropion – loosening of the eyelid causing it to turn outward, away from the eye

Entropion – “collapsing” of the eyelid, causing the edge of the lid to turn inward, toward the eye-often results in discomfort due to eyelashes rubbing against the eye

Epiretinal Membrane – wrinkling of the surface of the retina; can cause blurriness or distortion in vision – severe cases can be treated with surgical removal

Esotropia – having an eye that turns inward

Exophthalmos – bulging forward of the eyes, sometimes caused by thyroid problems

Exotropia – having an eye that turns outward

Fuchs’ Dystrophy – a deterioration of the cells in the cornea that maintain the cornea’s clarity; often has no visual effect but may require a corneal transplant if severe

Hemianopia – the loss of one half of the visual field (left or right); usually affects both eyes and is often caused by brain injury, especially stroke

Hyphema – bleeding inside the eye, often due to an injury

Herpes Simplex – a cause of serious corneal infection – the same virus that causes cold sores

Herpes Zoster – “shingles” – the same virus that causes chicken pox, which can return and affect many areas of the body, including the eye

Iritis – inflammation inside the eye, primarily in the front of the eye – causes redness, pain, blurred vision and sensitivity to light in most cases

Keratitis – inflammation in the cornea-may cause scratchiness, pain, blurred vision and light sensitivity

Keratoconus – a progressive change in the shape of the cornea, creating a “cone” – like configuration and causing blurred vision – severe cases may require a corneal transplant

Macular Oedema – swelling in the centre of the retina caused by fluid leakage; results in blurred vision and visual distortion

Neovascularization – growth of new abnormal blood vessels – can occur at several locations in the eye

Nystagmus – oscillating movements of the eye

Ocular Migraine – a visual disturbance usually including an arc of zigzag light and blurry vision – disappears spontaneously and does not usually include a headache

Optic Neuritis – inflammation of the optic nerve, resulting in blurred vision or other visual disturbances – can be caused by multiple sclerosis

Papilledema – swelling of the optic nerve where it enters the eye – can be caused by increased fluid pressure around the brain

Pinguecula – a thickening of the white of the eye; often caused by chronic irritation

Pterygium – growth of tissue from the white of the eye over the cornea – may interfere with vision if it nears the centre of the cornea

Ptosis – droopiness of the eyelid – may result from nerve or muscle damage, and sometimes requires surgical correction

Retinal Detachment – separation of the retina from its normal location covering the inner surface of the back portion of the eye

Rubeosis – growth of abnormal blood vessels on the iris

Scotoma – a blind spot

Strabismus (Squint) - any misalignment of the eye

Stye – an acute inflammation of a gland at the base of an eyelash, caused by bacterial infection.

Trichiasis – abnormal eyelash growth, usually pointing toward the eye

Uveitis – inflammation of the interior of the eye

Vitreous Detachment – separation of the vitreous gel from the back of the eye – a common occurrence which can result in sudden floaters and occasionally causes a tear in the retina