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Accommodation (uh-kah-muh-DAY-shun). The
ability of the eye and specifically crystalline lens inside the
eye to focus on near objects
After-cataract (secondary cataract). After-cataracts
are a type of cataracts that form after surgery for other eye problems,
such as glaucoma. After-cataracts also can develop in people who have
other health problems, such as diabetes. They are sometimes linked to
steroid use
Amsler grid (AM-slur). A small grid that tests
for retinal disorders, and is sometimes given to macular degeneration
patients to take home in order to monitor any changes in their condition
Angle, anterior chamber angle. The area in the
front of the eye where fluid from inside the eye drains out
Aphakia (ay-FAY-kee-uh). Once a patient has had
a cataract removed, the eye is considered “aphakic”.
If an intra-ocular lens is put in, which is typical, the eye is
considered “pseudo-phakic”
Aqueous (AY-kwee-us). The liquid that fills the
front chamber of the eye to keep the eye round and the cornea nourished
A-scan. A measurement of the length of the eye taken
before cataract surgery to properly determine the power of the lens
implant
Asthenopia (as-then-OH-pee-uh). Any type of uncomfortable
feeling in the eye, or eyestrain
Astigmatism (uh-STIG-muh-tiz-um). An irregular
shape to the cornea causes this common refractive error that can
usually be corrected with glasses or contact lenses
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Bifocals. Glasses that correct for blurred vision far away
and up close
Binocular vision. The two eyes working together
to see one image without eyestrain
Blepharitis (blef-uh-RI-tus). A common bacterial
infection of the eyelids and eyelashes, requiring special hygiene
measures and at times prescription medication
Blind spot. An area in the field of vision where
objects cannot be seen. Everyone has a normal “physiologic”
blind spot, but other blind spots from strokes, glaucoma or other
diseases are not normal
B-scan. A 2 dimensional ultrasound view of the
inside of the eye, useful in looking beyond a cloudy cornea or hemorrhage
in the eye to determine the health of the retina.
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Cataract. A clouding of the normally clear human lens inside
the eye, causing vision to be blurred.
Cataract extraction. A surgical procedure done
with ultrasound that removes the cloudy lens to restore vision
Central retinal artery. The main artery that supplies
blood to the eye
Central retinal vein. The main vein that circulates
used blood from the eye back to the heart
Central vision. Straight ahead vision, when you
look directly at someone or at a book to read
Chalazion (kuh-LAY-zee-un). A stye on the eyelid
which is the result of a blocked tear duct or infection
Choroid (KOR-oyd). The middle layer of the eyeball
that provides nourishment to the retina
Color blindness. The lack of ability to distinguish colors,
which can be inherited or acquired from a retinal disease
Cone. A type of retinal nerve cell that is responsible
for central vision and color vision
Conjunctiva (kahn-junk-TI-vuh). The clear outer
membrane covering the eye
Conjunctivitis (kun-junk-tih-VI-tis). Sometimes
referred to as “pink eye”, an infection of the outer
layer of the eye that can be caused by a bacterial or viral infection
Convergence (con-VER-genc-es). The ability of the eyes to move in
toward each other, as when one is reading or looking at a near target
Cornea (KOR-nee-uh). The clear front covering of
the eye, and the first surface where light is focused onto the retina
Cross-eyes. See esotropia
Crystalline lens. The clear human lens inside the
eye, that along with the cornea, focuses light onto the retina to
create a clear image
Cycloplegic refraction. Measurement of the eyeglass
prescription after drops are instilled in the eye to “freeze”
the focusing mechanism. Often done on children to obtain an accurate
assessment of the actual prescription
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Diabetic retinopathy (ret-in-AHP-uh-thee). Hemorrhages
and abnormal blood vessels seen in the retina of diabetics, especially
those whose disease is not controlled well
Dilated pupil. A large pupil usually created by
pharmacologic agents to allow a better look inside the eye
Diopter(D) (di-AHP-tur). A unit of measurement
that describes the refractive power of a lens
Diplopia. Double vision, or seeing two or more
objects when there is only one
Drusen (DRU-zin). Small yellow or white deposits
in the retina frequently associated with macular degeneration
Dry eye syndrome. A lack of tears produced by the
eye’s lacrimal gland, thought to result from inflammation.
This syndrome often leads to discomfort, specifically stinging,
burning and a scratchy feeling
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Ectropion (ek-TROH-pee-un). The lower eyelid can lose
its elasticity, causing it to turn outward, which sometimes can
result in tear drainage problems and excessive tearing
Emmetropia (em-uh-TROH-pee-uh). The refractive
condition whereby light is focused perfectly on the retina, and
the person sees 20/20 without any form of visual correction
Entropion (en-TROH-pee-un). The lower eyelid turns
inward, often resulting in eyelashes contacting the front of the
eye with resultant irritation
Esotropia (ee-soh-TROH-pee-uh). An inward turning
of the eye, commonly known as “crossed eyes”
Excimer laser (EKS-ih-mur). An ultraviolet laser
that removes human tissue precisely and without heat, thereby shaping
the eye to reduce refractive errors such as reducing nearsightedness
(LASIK or PRK)
Exotropia (eks-oh-TROH-pee-uh). An outward turning
of the eye, commonly known as “wall-eye”
Extraocular muscles (eks-truh-AHK-yu-lur). The
muscles that control eye movements, such as when one looks up, down
or to the left or right
Eyelids. The thin membrane of skin that is designed
to protect the eye and keep it from drying out
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Farsightedness. See hyperopia.
Fluorescein Angiography (FLOR-uh-seen an-jee-AH-gruh-fee).
A dye is injected into the vein and high speed photographs are taken
to look at the blood flow in the retina, meant to detect leakage
of abnormal blood vessels such as in diabetes or macular degeneration
Fovea (FOH-vee-uh). The very central part of the
retina, used for fine focus distance and near vision
Fundus. The back of the eye, including the optic
nerve and retina
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Glaucoma (glaw-KOH-muh). A progressive disease of the
optic nerve, often but not necessarily associated with high intraocular
pressure, leading to slow deterioration of side (peripheral) vision.
If there is a family history of glaucoma, other family members have
up to a ten fold chance of developing the disease and should be
checked yearly
Gonioscopy (goh-nee-AHS-koh-pee). A technique
to look at the angle, the area of the eye where fluid drains out,
which can be abnormal in people with glaucoma
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Hyperopia (hi-pur-OH-pee-uh). Also known as far-sightedness,
where distant objects are seen more clearly that print/objects up
close
Hyphema (hi-FEE-muh). A hemorrhage inside the eye,
often resulting from blunt trauma
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IOL (intraocular lens). An artificial lens, typically made
of silicone or acrylic material, that is implanted in the eye at the
time of cataract surgery to replace the cloudy human lens that is
removed Iris. The colored part of the eye,
which constricts or dilates depending on lighting conditions
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Keratoconus (kehr-uh-toh-KOH-nus). A condition that causes
the cornea to warp or bulge, leading to a large degree of astigmatism
which requires treatment with either a rigid contact lens or a corneal
transplant procedure
Keratometry (kehr-uh-TAH-mih-tree). A measurement of the curvature of the cornea
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Lacrimal gland. The gland behind the upper eyelid that
produces tears
Laser. A powerful beam of light that is used in a variety of forms
of surgery to remove or vaporize tissue
LASIK (LAY-sik). Stands for “Laser Assisted
In Situ Keratomileusis” which involves cutting a flap on the
cornea, lifting it, and reshaping the cornea below with an excimer
laser to reduce nearsighted or farsightedness, then replacing the
flap
Legal blindness. Typically defined in the U.S.
as visual acuity (with glasses) worse than 20/200 in the better
seeing eye, or in combination with significant peripheral vision
loss
Lens, crystalline lens. The lens inside the eye
that, along with the cornea, bends (refracts) light onto the retina
in order to create a sharp focus, allowing us to see clearly
Low vision. The optometric specialty that involves
helping those who are legally blind to use their remaining vision
using strong magnifiers, telescopes, and daily living aids
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Macula. The very sensitive central part of the retina responsible
for fine focus vision and the perception of colors
Myopia (mi-OH-pee-uh). Also known as nearsightedness. where
objects up close are seen more clearly than distant objects
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Nearsightedness. See myopia
Neovascularization (nee-oh-VAS-kyu-lur-ih-ZAY-shun).
The formation of abnormal blood vessels, as seen in poorly controlled
diabetes, which can lead to hemorrhages and retinal detachment
Nystagmus (ni-STAG-mus). Rapid involuntary eye
movements that may be the result of poor vision, or a neurological
condition
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Ophthalmologist (ahf-thal-MAH-loh-jist). An eye doctor
who specializes in the diagnosis and treatment of eye diseases and
surgery of the eye
Ophthalmoscope (ahf-THAL-muh-skohp). A lighted instrument used to examine the back of the eye, specifically
the optic nerve and retina, to rule out conditions such as retinal detachment,
diabetes, glaucoma, etc.
Optic disc.
The point where the optic nerve enters the retina; not sensitive to light
Optic nerve. The main nerve of the eye which carries
visual information from the retina to the visual interpretation
centers of the brain
Optician (ahp-TISH-un). A professional who specializes
in making and fitting eye glasses
Optometrist (ahp-TAHM-uh-trist). An eye doctor
who specializes in primary care of the eye, including correction
of the visual system and the diagnosis and treatment of eye diseases
Orthoptics. Eye exercises designed to strengthen
eye muscles and improve the way the eyes work together and focus
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Patching. Covering an amblyopic patient's preferred eye,
to improve vision in the other eye.
Perimetry (puh-RIM-ih-tree). The measurement of
the peripheral or side vision, often done with an automated computerized
instrument
Peripheral vision. Side vision, or the awareness
of objects coming from outside the straight ahead line of sight
Phacoemulsification (fay-koh-ee-mul-sih-fih-KAY-shun).
An ultrasound technique used to break up the cloudy lens (cataract)
inside the eye, allowing for a smaller incision
Photophobia (foh-toh-FOH-bee-uh). Sensitivity to
light or glare
Pinguecula (pin-GWEK-yu-luh). A growth on the outside
of the eye, typically in the inner or outer corner, thought to be
related to long term exposure to ultraviolet sunlight
Pink eye. See conjunctivitis
Presbyopia (prez-bee-OH-pee-uh). A condition that
commonly develops after age 40, resulting from aging changes to
the human lens and a lack of ability to focus up close requiring
reading glasses
PRK (photorefractive keratectomy). Stands for Photo
Refractive Keratectomy, a procedure to reduce or eliminate nearsightedness
by scraping the outer layer of the cornea and using an excimer laser
to shape the eye
Progressive Addition Lens (PAL). Invisible bifocals
that focus light at a variety of intermediate and near distances
Proliterative retinopathy. See diabetic retinopathy
Pterygium (tur-IH-jee-um). A vascular growth on
the outside of the eye, typically in the inner or outer corner,
thought to be related to long term exposure to ultraviolet sunlight
that can grow onto the cornea and affect vision
Ptosis (TOH-sis). A droopy upper eyelid
Pupil. The hole in the center of the iris that
light is directed through onto the retina
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Radial keratotomy (RK) (keh-ruh-TAH-tuh-mee). A surgical
procedure, popular in the 1970’s and 80’s, that used eight
spoke-like incisions to induce flattening of the cornea and correct nearsightedness.
RK has been replaced by LASIK and PRK
Refraction. The measurement of the visual system
to determine the appropriate eyeglass or contact lens prescription
Refractive error. The amount of nearsightedness,
farsightedness or astigmatism that an individual has
Retina (RET-ih-nuh). The inner lining of the eye,
consisting of sensitive nerve cells that receive light images and
converts them to electrical impulses that are sent the brain by
way of the optic nerve
Retinal detachment. A separation of the retina
from the layers behind it, usually resulting from injury or seen
in patients who are highly nearsighted. A retinal detachment can
be surgically repaired but the amount of vision recovered depends
on the extent of the detachment and how quickly it is diagnosed.
Retinoscope (RET-in-oh-skohp). An instrument used
to determine the refractive error of the eye by shining a light
in the eye and observing the reflected light images
Rod. A type of retinal nerve cell responsible for night vision and
peripheral vision
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Schlemm's canal (shlemz). The drainage channel where fluid
exits the eye
Sclera (SKLEH-ruh). The white protective outer coating of the eye
Secondary cataract. See after-cataract
Slit lamp. Also called a biomicroscope, used to
magnify structures in the front and back of the eye to examine various
structures and diagnose abnormal conditions
Snellen chart. A vision chart that is read to
determine one’s visual acuity, or clarity of vision
Strabismus (struh-BIZ-mus). A misalignment of the
eyes, often leading to double vision
Sty, stye. See chalazion
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Tonometry (tuh-NAH-mih-tree). The measurement of the pressure
inside the eye, often related to glaucoma
Trabecular meshwork (truh-BEK-yu-lur). The drainage
channel in the front of the eye, and the area that is lasered in
glaucoma that does not respond to medication
Trifocal (TRI-foh-kul). A segmented lens for up
close, with one section for intermediate (computer) range and another
for reading vision
20/20. The smallest line of the eye chart that
someone with perfect vision can see
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Uvea, uveal tract (YU-vee-uh). The middle layer of the
eye, sandwiched between the retina and choroid, that supplies the
eye with nutrients via the blood vessel system
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Visual acuity. The level of clarity of vision
Visual field. The total area that can be seen both
straight ahead and to the side
Vitreous (VlT-ree-us), vitreous humor. The gel
like substance that fills the back chamber of the eye, helping keep
the eye round
Vitreous detachment. A separation of the gel like
vitreous from the retina, in some cases leading to a retinal tear
or detachment
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