Glossary of Eye Terms

Astigmatism: Irregular corneal shape (like an egg or a football) resulting in blurred vision

Amblyopia: Abnormal visual development where the brain favors one eye over the other, causing the weaker eye (the “lazy” eye) to wander. (See Lazy Eye)

Blepharitis: Infection of the eyelid

Cataract: Clouding of the normally-clear lens of the eye, results in obstructed vision

Central Serous Retinopathy: small swelling on the retina, typically self-healing, sometimes stress-related

ChalazionSwelling of eyelid, caused by inflammation of an oil-producing gland in the upper or lower eyelid

CMV Retinitis: Serious infection of the retina, particularly risky to individuals with weak immune systems

Coats’ Disease: Chronic, progressive disorder of the retina

Conjunctivitis“pink eye”, a contagious infection/inflammation of the clear covering of the white of the eye

Cornea: The clear “window” that covers the colored part of the eye

Corneal AbrasionSurface-level injury to the cornea

Detached RetinaAn emergency situation where the retina pulls away from the layer of blood vessels supplying oxygen and nourishment; there is risk of blindness if left untreated

Diabetic Retinopathy: Complication of diabetes; caused by damage to the blood vessels of the retina

Dry EyeCondition caused by the erosion or diminishing of the eye’s protective tear layer

Eyelid Tumor Abnormal growth in the eye area

Farsightedness: Ability to see distant objects clearly; near objects appear blurry (hyperopia)

FloaterSmall, dark speck moving around in your field of vision; may resemble shadows or cobwebs or “floating bugs”

Flash: Similar to a floater, but resembling a twinkle or lightning streak; “seeing stars”

Glaucoma: Disease of the optic nerve; causes peripheral vision loss if left untreated

Herpes Simplex Eye Disease: Complication of HSV type 1, results in a recurrent infection of the cornea (clear window of eye, covering the colored part); can potentially threaten vision

Intravitreal Injections in the Treatment of Diabetic RetinopathyInjections of potent medications in the eye are now commonly done in the office, and the results are usually very good. The injections are done with a local anesthetic, can be done very rapidly (usually less than a few seconds for the actual injection), and are usually associated with only a minimum amount of discomfort during and after the procedure. There are risks associated with the injections, just as there are with any surgical procedure, but these are very rare.

Ischemic Optic Neuropathy“Stroke” of the optic nerve (the messenger which carries sight input to the brain); results in sudden loss of vision

Keratoconus: “Cone-shaped” cornea; uncommon condition where the cornea thins and protrudes

Laser In the Treatment of Diabetic RetinopathyThe main goal of laser treatment is to prevent further loss. In a sense, it “freezes” the symptoms and keeps them from getting worse. Many people experience improvement; however, in most cases, “perfect” vision will not be completely recovered after laser treatment. Multiple laser treatments over time are sometimes necessary. Laser surgery does not cure diabetic retinopathy and does not always prevent further loss of vision.

Lazy Eye: Abnormal visual development where the brain favors one eye over the other, causing the weaker eye (the “lazy” eye) to wander. See amblyopia.

Low VisionVisual impairment that is not significantly improved by ordinary vision correction or IOL implants; distinct from blindness

Maculasmall area in the center of the retina that allows us to see fine details clearly

Macular DegenerationDistorted, blurred vision caused by the breakdown of the macula (central portion of the retina)

Macular Edema: The swelling or thickening of the macula caused by fluid leakage from the retinal blood vessels. It is the most common cause of visual loss in diabetes.

Macular Ischemia: Occurs when small blood vessels (capillaries) close. Vision blurs because the macula no longer receives sufficient blood supply to function properly.

Misaligned EyesCondition where one eye gazes straight ahead, and the other turns inward, outward, upward or downward

Nearsightedness:  Ability to see near objects clearly, while distant objects appear blurry (also, myopia)

Ocular Histoplasmosis Syndrome (OHS): a complication of histoplasmosis (disease caused by fungus exposure); must be treated by a form of laser surgery known as photocoagulation.

Optic Nerve: bundle of nerves joining the retina to the brain

Optic Neuritisinflammation of the optic nerve

Optical: pertaining to eyeglasses and contact lenses

Optician: someone trained to make vision correcting lenses and adjust eyewear

Presbyopia: gradual loss of lens elasticity that makes it difficult to focus on near objects; a natural result of aging

Ptosis: drooping of the upper eyelid that can block vision

Retina: thin layer of tissue at the back of the eye; transforms light into nerve signals

Retinal Vein Occlusion: a blockage in a vein in the back of the eye, causes retinal swelling and poor functioning

Retinitis Pigmentosa: disease which affects the rods and cones of the light-sensitive nerve layer at the back of the eye; night blindness and/or tunnel vision is symptomatic

Retinoschisis: genetic eye disease that splits the nerve layer at the back of the eye

Sclera: the white part of the eye

Stargardt’s Disease: an inherited disease that affects the retina; usually apparent between the ages of 8-14

Strabismus/Psuedostrabismus: misaligned eyes, or the false appearance of

Tearing: watery eyes, excessive tear production; potential causes include allergies, dry eye, infection, or another ocular condition

Toxoplasmosis: common parasitic infection that can settle in the macula and cause permanent damage

Vitreousclear gel inside the eye that fills the space between the lens and the retina