Ablate: In refractive surgery, means "to remove".

Ablation zone: Area of cornea tissue that is removed during surgery.

Accommodation: Ability of the eye to change its focus from distant objects to near objects.

Acuity: Clearness or sharpness of vision.

Astigmatism: Distortion of the image on the retina caused by irregularities in the cornea. May also be called a refractive error.

Cornea: The clear front part of the eye.

Diopter: Measurement of refractive error of the eye.

Dry eye: Common condition that occurs when the eyes do not produce enough tears to lubricate the eye. Symptoms include burning, stinging or itchiness.

Endothelium: Inner layer of cells on the inside surface of the cornea.

Epithelium: Outermost layer of cells of the cornea and the eye’s first defense against infection.

Excimer laser: An ultraviolet laser used in refractive surgery to remove corneal tissue.

Farsighted: Common term for hyperopia. May also be called a refractive error.

FDA : U.S. Food and Drug Administration, the government agency responsible for the evaluation and approval of medical devices.

Ghost image: A fainter second image of the object you are viewing.

Halos: Rings around lights.

Top

Haze: Cornea clouding that causes the sensation of looking through smoke or fog.

Hyperopia: Ability to see distant objects more clearly than close objects. May also be called a refractive error.

Inflammation: Tissue’s reaction to trauma. Often associated with pain, heat, redness, swelling and/or loss of function. It can be caused by mechanical trauma, infections, bacteria and viruses.

In situ: Means “in place”, or not removed

Iris: Colored ring of tissue suspended behind the cornea and immediately in front of the lens.

Keratectomy: surgical removal of corneal tissue

Keratotomy: Surgical incision of the cornea

Keratitis: Inflammation of the cornea

Kerato-: A prefix indicating relationship to the cornea

Keratomileusis: Carving of the cornea done with an excimer laser.

Top

Laser : Instrument that produces a beam of light and can vaporize tissue.

Lasik : Laser Assisted In Situ Keratomileusis. A surgical procedure in which the doctor creates a flap with a microkeratome, then uses a laser to reshape the underlying cornea.

Lens: Part of the eye that provides some focusing power.

Microkertaome: Surgical device that when placed on the eye cuts a very small amount of cornea at a predetermined depth.

Monovision: Adjustment of one eye for near vision and the other eye for distance vision.

Myopia: Inability to see distant objects clearly. May also be called a refractive error.

Nearsightedness: Common term for myopia. May also be called a refractive error.

Ophthalmologist: Medical doctor specializing in the diagnosis and treatment of visual disorders and diseases. Can perform surgery

Optician : Expert in making and fitting eyeglasses.

Optometrist: Primary eye care provider who diagnosis and manages disorders of the visual system.

Over-correction: Complication of refractive surgery where the expected amount of vision correction is more than desired. Often occurs when healing regresses less vigorously than predicted.

Top

PRK : Photo-refractive keratectomy. The procedure which removes the surface layer by gently scraping and using a computer-controlled excimer laser to reshape the cornea.

Presbyopia: Normal part of aging caused when the flexibility of the eye decreases and limits the ability of the eye to change its focus from close to far away. Corrected by reading glasses or laser eye surgery. May also be called a refractive error.

Pupil: Part of the eye that appears as a small black dot in the center of the iris and changes its diameter in response to light.

Radial keratotomy: Surgical procedure designed to correct myopia (nearsightedness) by flattening the cornea. Also called RK.

Refraction: Test to determine the best eye glasses or contact lenses to correct a refractive error (myopia, hyperopia, astigmatism) or the bending of a light by use of a lens or other material.

Refractive error: Hyperopia, myopia, astigmatism and presbyopia.

Retina: Part of the eye that lines the inside wall and consists of fine sensory tissue. The retina acts like a camera to capture and transmit images to the brain.

Sclera: White, outer layer (coat) of the eyeball and, with the cornea, protects the entire eyeball.

Stroma: Thick, middle layer of the cornea.

Under-correction: Complication of refractive surgery where the expected amount of correction is less than desired or occurs when healing regresses more vigorously than predicted

Visual acuity: Clearness of vision or the ability to distinguish details and shapes or objects.