macula: The small, central area of the retina that provides high-acuity vision.
macular degeneration: A disease in which the tissues of the macula break down, causing hemorrhaging and/or scarring, causing a loss of sharp, central vision. Though painless, its effects are not reversible and it is the leading cause of blindness in patients over 60.
monovision: A type of refractive correction in which one eye is corrected for distance vision and one eye is corrected for near vision. This can be accomplished through refractive surgery or corrective lenses.
multifocal: A lens that provides more than one area of focus, such as near vision and distance vision. Generally used to treat presbyopia along with near- or farsightedness.
myopia: Commonly called “nearsightedness,” myopia is a refractive error where the light entering the cornea focuses ahead of the retina. The patient’s near vision is clear, but distance vision is blurred.
ophthalmologist: A medical doctor specializing in the diagnosis and treatment of diseases and disorders of the eye.
optic nerve: A bundle of nerve fibers that carry images from the retina to the brain.
optician: A professional who uses a refraction provided by an ophthalmologist or optometrist to make or dispense corrective eyewear.
optometrist: A licensed medical professional (doctor of optometry), who provides primary eye care services such as eye examinations, the diagnosis and treatment of certain eye conditions and the prescription of visual aids such as glasses and contact lenses.
photophobia: An extreme sensitivity to light.
posterior capsular opacity: Also called a “secondary cataract” this is the clouding of the capsule that holds the lens implant after cataract surgery, resulting in decreased vision.
presbyopia: The aging of the eye. The gradual loss of near vision, caused by a decreased flexibility of the eye’s crystalline lens. This results in the need for reading glasses for close tasks.
PRK (photorefractive keratectomy): A surgical procedure aimed at correcting refractive error in the eye. It involves the removal of the top layer of the cornea followed by the reshaping the cornea with an excimer laser to correct nearsightedness, farsightedness and/or astigmatism. This is an alternative to LASIK.
PAL (progressive addition lenses): Eyeglass lenses used to correct myopia or hyperopia as well as presbyopia. The upper portion of the lens has the distance prescription while the prescription gradually changes to the reading addition on the bottom. Unlike bifocals, these lenses have a gradual change, so there is no line to differentiate powers.
pterygium: A non-cancerous, raised growth in the eye, generally caused by prolonged exposure to the sun. Symptoms can range from a foreign body sensation in the eye to irregular astigmatism and blurred vision depending on the size and location of the growth. In some cases, surgical removal is necessary.
punctual plug: A treatment for dry eye that involves the insertion of tiny silicone plugs into the tear ducts. These plugs block the drainage of fluid through the duct, increasing the surface moisture of the eye.
pupil: The black area in the center of the iris, which adjusts to let varying levels of light into the eye.