refractive surgery: a surgical procedure that corrects problems with visual acuity with the objective of reducing or eliminating the need for prescription glasses or contact lenses.
retina: a thin layer of light sensitive nerve tissue lining the interior of the eye that translates light waves into nerve impulses that are sent to the brain.
retinal detachment: occurs when the retina separates from the rear wall of the eye. Vision loss occurs at these detached areas.
retinitis pigmentosa: a genetically inherited condition in which rod cells degenerate causing impaired vision in low light conditions and may eventually lead to diminished peripheral perception.
RGP: Rigid Gas Permeable; a type of contact lens that is made of a permeable plastic that is custom made to the shape of the cornea and allows for oxygen to pass through the lens to the eye.
rods: light-sensitive cells located in the peripheral (side) areas of the retina. They are responsible for detecting movement, shape, light and dark. The visual picture provided by rods is in black and white.
RK: Radial Keratotomy; a surgical procedure in which several incisions are made in the cornea in a radial or spoke-like pattern in order to flatten the cornea and correct for myopia.
sclera: the outer layer of the eye that forms the visible white area of the eye and extends from the cornea in the front of the eye to the back of the eye where it meets and surrounds the optic nerve.
strabismus: "crossed eyes"; a condition in which the one or both of the eyes are misaligned caused by poor muscular control. The condition often occurs in children before 21 months of age but may develop as late as age 6. Treatments include corrective eyewear, visual therapy, or surgery.
sty: an inflammation of the eyelid near the eyelash caused by a blockage of a gland in the eyelid due to bacterial infection.
toric lenses: a lens used to correct astigmatism by providing two different optical powers at 90-degree angles to each other.
trifocal: a lens designed with three different focal areas. Often the top segment provides distance correction, a center segment corrects for intermediate distances, and the lower portion corrects for near objects and reading.
