Diopter
the measurement of refractive error. A negative diopter value signifies
an eye with myopia and positive diopter value signifies an eye with hyperopia.
Dry
Eye Syndrome a common condition that occurs when the eyes do
not produce enough tears to keep the eye moist and comfortable. Common
symptoms of dry eye include pain, stinging, burning, scratchiness, and
intermittent blurring of vision.
Endothelium
the inner layer of cells on the inside surface of the cornea.
Epithelium
the 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.
Farsightedness
the common term for hyperopia.
FDA
the abbreviation for the Food and Drug Administration. It is the United
States governmental agency responsible for the evaluation and approval
of medical devices.
Flap
& Zap a slang term for LASIK.
Ghost
Image a fainter second image of the object you are viewing.
Glare
scatter from bright light that decreases vision.
Halos
are rings around lights due to optical imperfections in or in front of
the eye.
Haze
corneal clouding that causes the sensation of looking through smoke or
fog.
Hyperopia
the inability to see near objects as clearly as distant objects, and the
need for accommodation to see distant objects clearly.
Inflammation
the body's reaction to trauma, infection, or a foreign substance, often
associated with pain, heat, redness, swelling, and/or loss of function.
Informed
Consent Form a document disclosing the risks, benefits, and alternatives
to a procedure.
In
Situ a Latin term meaning "in place" or not removed.
Iris
the colored ring of tissue suspended behind the cornea and immediately
in front of the lens.
Keratectomy
the surgical removal of corneal tissue.
Keratotomy
a surgical incision (cut) of the cornea.
Keratitis
inflammation of the cornea.
Kerato
prefix indicating relationship to the cornea.
Keratoconus
a disorder characterized by an irregular corneal surface (cone-shaped)
resulting in blurred and distorted images.
Keratomileusis
carving of the cornea to reshape it.
Laser
the acronym for light amplification by stimulated emission of radiation.
A laser is an instrument that produces a powerful beam of light that can
vaporize tissue.
LASIK
the acronym for laser assisted in situ keratomileusis which refers
to creating a flap in the cornea with a microkeratome and using a laser
to reshape the underlying cornea.
Lens
a part of the eye that provides some focusing power. The lens is
able to change shape allowing the eye to focus at different distances.
Microkeratome
a surgical device that is affixed to the eye by use of a vacuum ring. When
secured, a very sharp blade cuts a layer of the cornea at a predetermined
depth.
Monovision
the purposeful adjustment of one eye for near vision and the other eye
for distance vision.
Myopia
the inability to see distant objects as clearly as near objects.
Nearsightedness
the common term for myopia.
Ophthalmologist
a medical doctor specializing in the diagnosis and medical or surgical
treatment of visual disorders and eye disease.
Optician
an expert in the art and science of making and fitting glasses and may
also dispense contact lenses.
Optometrist
a primary eye care provider who diagnoses, manages, and treats disorders
of the visual system and eye diseases.
Overcorrection
a complication of refractive surgery where the achieved amount of correction
is more than desired.
PRK
the acronym for photorefractive keratectomy which is a procedure involving
the removal of the surface layer of the cornea (epithelium) by gentle scraping
and use of a computer-controlled excimer laser to reshape the stroma.
Presbyopia
the inability to maintain a clear image (focus) as objects are moved closer.
Presbyopia is due to reduced elasticity of the lens with increasing age.
Pupil
a hole in the center of the iris that changes size in response to changes
in lighting. It gets larger in dim lighting conditions and gets smaller
in brighter lighting conditions.
Radial
Keratotomy commonly referred to as RK; a surgical procedure
designed to correct myopia (nearsightedness) by flattening the cornea using
radial cuts.
Refraction
a test to determine the refractive power of the eye; also, the bending
of light as it passes from one medium into another.
Refractive
Errors hyperopia, myopia, and astigmatism.
Refractive
Power the ability of an object, such as the eye, to bend light
as light passes through it.
Retina
a layer of fine sensory tissue that lines the inside wall of the eye. The
retina acts like the film in a camera to capture images, transforms the
images into electrical signals, and sends the signals to the brain.
Sclera
the tough, white, outer layer (coat) of the eyeball that, along with the
cornea, protects the eyeball.
Snellen
Visual Acuity Chart one of many charts used to measure vision.
Stroma
the middle, thickest layer of tissue in the cornea.
Undercorrection
a complication of refractive surgery where the achieved amount of correction
is less than desired.
Visual
Acuity the clearness of vision; the ability to distinguish details
and shapes.
Vitreous
Humor the transparent, colorless mass of gel that lies behind
the lens and in front of the retina and fills the center of the eyeball.
