Eye Conditions and Useful Terms

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

For more definitions and medical conditions visit www.online-medical-dictionary.org

A

Achromatopsia- A hereditary condition in which people lack certain receptors in their retinas, causing them to be nearly or completely colorblind and to have poor vision acuity.

Alpha-2 agonists- A medication used to treat glaucoma that helps by inhibiting the production and increasing the draining of aqueous humor, thereby reducing the pressure inside the eye.

Amblyopia- A condition that occurs in children in which one eye has poorer vision than the other. If Amblyopia is left untreated, a child's vision will not develop correctly and as the brain matures, one eye will remain with poor vision.

Anterior Chamber- the area bound in front by the cornea and in back by the lens, and filled with aqueous.

Aqueous- a clear, watery solution in the anterior and posterior chambers.

Aqueous Humor- The clear, watery fluid between the lens and the cornea.

Astigmatism- A condition in which blurred vision is caused by the cornea being shaped more like a football than spherical. Astigmatism may be compensated for through eyeglasses or contacts or can be corrected through refractive surgery.

Back To Top

B

Beta-blocker- A medication used in the treatment of glaucoma. Beta-blocker eye drops help reduce the pressure within the eye by reducing the production of aqueous humor.

Back To Top

C

Carbonic anhydrate inhibitor- A type of medication used to treat glaucoma. Carbonic anhydrate inhibitors work by reducing the production of aqueous humor, thereby reducing the pressure inside the eye.

Choroid- The layer of blood vessels between the retina and the sclera.

Choroiditis- A form of uveitis that causes an inflammation of the layer beneath the retina. It may also be caused by an infection such as tuberculosis.

Conjunctiva- a clear membrane covering the white of the eye (sclera).

Conjunctivitis- Inflammation of the conjunctiva.

Cornea- a clear, transparent portion of the outer coat of the eyeball through which light passes to the lens.

Cryotherapy- A surgical procedure in which abnormal cells are destroyed by freezing them.

Cyclitis- A form of uveitis that causes inflammation of the middle portion of the eye and may affect the muscle that focuses the lens. Cyclitis may develop suddenly and last several months.

Back To Top

D

Dilation- Expansion.

E

Enucleation- A procedure in which the eye is removed.

F

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.

Flip & Zap- A slang term for LASIK.

G

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

Glare- Scatter from bright light that decreases vision.

Back To Top

H

Halos- 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- A condition in which a person has difficulty seeing objects up close, but objects further away are seen clearly. Hyperopia is commonly referred to as farsightedness.

I

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 that discloses the risks, benefits, and alternatives to a procedure.

Intraocular- Of or related to the inside of the eye.

In Situ- a latin term meaning "in place" or not removed.

Iris- it gives our eyes color and it functions like the aperture on a camera, enlarging in dim light and contracting in bright light. The aperture itself is known as the pupil.

Iritis- The most common form of uveitis, it affects the iris and is often associated with autoimmune disorders such as arthritis. Iritis may develop suddenly and may last up to eight weeks, even with treatment.

Back To Top

J

K

Keratectomy- The surgical removal of corneal tissue.

Keratotomy- The 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.

L

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 the microkeratome and using a laser to reshape the underlying cornea.

Legal blindedness- Having a visual acuity that cannot be corrected to better than 20/200 or having 20 degrees or less (tunnel vision) of visual field eyeglasses.

Lens- the lens helps to focus light on the retina.

Low Vision- A condition in which a person is either legally blind and thus has visual acuity of less than 20/200 or is partially sighted and has a visual acuity between 20/70 and 20/200 despite the use of conventional corrections such as prescription eyeglasses.

M

Macula- a small area in the retina that provides our most central, acute vision.

Macula Edema- A swelling of the macula that can cause vision to become blurred or impaired. It is usually caused by an injury or disease.

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 the predetermined depth.

Monovision- The purposeful adjustment of one eye for near vision and the other eye for distance vision.

Myopia- A condition in which a person has difficulty seeing objects in the distance. Myopia is commonly referred to as nearsightedness.

N

Nearsightedness- The common term for myopia

Nightblindedness- A condition in which a person has impaired vision in dim or darkened conditions. Night blindedness is commonly caused by a deficiency in vitamin A.

Nyctalopia- See night blindedness.

O

Ocular- Of or relating to the eye.

Ophthalmologist- Ophthalmologists are doctors who specialize in the medical and surgical care of the eyes and visual system, and also the prevention of eye disease and injury. They can be either doctors of medicine (MD) or doctors of osteopathy (OD). As a qualified specialist, an ophthalmologist is qualified to deliver total eye care, meaning vision services, eye examinations, medical and surgical eye care, diagnosis and treatment of disease, and visual complications that are caused by other conditions, like diabetes.

Ophthalmoscope- An instrument used to examine the retina. There are two types of ophthalmoscopes; direct and indirect. The direct version is used to examine the center of the retina, while the indirect version is used when an examination of the entire retina is needed.

Optician- An expert in the art of science of making and fitting glasses and may also dispense contact lenses.

Optic Nerve- the optic nerve conducts visual impulses to the brain from the retina.

Optometrist- A medical specialist trained to examine, diagnose, treat, and manage some diseases and disorders of the eye. Like ophthalmologists, optometrists are trained to examine the internal and external structure of the eyes to detect diseases such as glaucoma, retinal diseases, and cataracts. Optometrists do not perform surgery and are not trained to care for and manage all diseases and disorders of the eyes. The optometrist is trained to diagnose and treat vision conditions like nearsightedness, farsightedness, astigmatism, and presbyopia.

Overcorrection- A complication of refractive surgery where the achieved amount of correction is more than desired.

P

Peripheral vision- The ability to see objects on the side, out of one's direct line of vision.

PhotoCoagulation- A surgical procedure in which a laser is used to stop bleeding blood vessels or to repair damaged tissue. Photocoagulation can also be used to help treat a tumor found in the eye.

Presbyopia- The loss of the eye's ability to change its focus to see objects that are near. Presbyopia is not a disease, but a part of the natural aging process of the eye that affects everybody at some point in life. It generally starts to appear around age 45.

Pupil- the opening, or aperture, of the iris.

Q

R

Radial Keratotomy- commonly referred to as RK; a surgical procedure designed to correct myopia (nearsightedness) by flattening the cornea using radial cuts.

Refraction- The ability of the eye to bend light so that an image focuses directly on the retina.

Refractive Errors- A condition in which light bends incorrectly, causing an image to be out of focus. The most common refractive errors are astigmatism, farsightedness, and nearsightedness.

Refractive Power- the ability of an object, such as the eye, to bend light as light passes through it.

Retina- the innermost coat of the back of the eye, formed of light-sensitive nerve endings that carry the visual impulse to the optic nerve. The retina may be compared to the film of a camera.

Retinitis pigmentosa- Any of a number of inherited disorders in which there is a progressive loss of vision. In general, patients with this disorder first experience a loss of night vision, which is then followed by tunnel vision and eventually a loss of central vision.

Retinoblastoma- A malignant tumor that forms on the retina. Retinoblastoma most often affects children under the age of 5. It can occur in one or both eyes.

Back To Top

S

Sclera- the white of the eye.

Snellen Visual Acuity Chart- one of many charts used to measure vision.

Strabismus- A condition in which the eyes are misaligned and unable to point in the same direction at the same time. Crossed eyes is an example of strabismus.

Stroma- The middle, thickest layer of tissue in the cornea.

T

Tunnel vision- A condition in which a person lacks any peripheral vision. Tunnel vision can be caused by any number of conditions including glaucoma, retinitis pigmentosa, and stroke.

Back To Top

U

Undercorrection- a complication of refractive surgery where the achieved amount of correction is less than desired.

V

Visual acuity- How well a person sees.

Visual field- The entire range in which a person can see, including peripheral vision.

Vitrectomy- A procedure in which the vitreous humor is removed from the eyeball and replaced with a clear gel or liquid. Vitrectomies are done when scarring or blood in the vitreous is causing blockage of vision.

Vitreous- a transparent, colorless mass of soft, gelatinous material filling the eyeball behind the lens.

Vitreous humor- The clear gel-like substance found inside the center of the eyeball.

Back To Top

W

X

Y

Z

Back To Top