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February 10, 2012


Vision Correction Surgery Glossary of Terms

The following are health and medical definitions of terms that appear in the Vision Correction Surgery article.

20/20: See; Twenty-twenty.

Ablation: Removal or excision. Ablation is usually carried out surgically. For example, surgical removal of the thyroid gland (a total thyroidectomy) is ablation of the thyroid. The word ablation comes from the Latin ablatum meaning to carry away.
See the entire definition of Ablation

Abrasion: An abrasion or "excoriation" is a wearing away of the upper layer of skin as a result of applied friction force. In dentistry an "abrasion" is the wearing away of the tooth substance.

Anisometropia: The condition in which the two eyes have an unequal refractive power. One eye may be myopic (nearsighted) and the other hyperopic (farsighted).
See the entire definition of Anisometropia

Anterior: The front, as opposed to the posterior. The anterior surface of the heart is toward the breast bone (the sternum).
See the entire definition of Anterior

Antibiotic: A drug used to treat infections caused by bacteria and other microorganisms. Originally, an antibiotic was a substance produced by one microorganism that selectively inhibits the growth of another. Synthetic antibiotics, usually chemically related to natural antibiotics, have since been produced that accomplish comparable tasks.
See the entire definition of Antibiotic

Arthritis: Inflammation of a joint. When joints are inflamed they can develop stiffness, warmth, swelling, redness and pain. There are over 100 types of arthritis. (see osteoarthritis, rheumatoid arthritis, ankylosing spondylitis, psoriatic arthritis, lupus, gout, pseudogout).

Astigmatism: A common form of visual impairment in which part of an image is blurred, due to an irregularity in the curvature of the front surface of the eye, the cornea. The curve of the cornea is shaped more like an American football or a rugby ball rather than a normal spherical basketball. Light rays entering the eye there are not uniformly focused on the retina. Rays entering through the more-curved surface are focused before the rays coming through the less-curved surface. The light is focused clearly along one plane but is blurred along the other. The result is blurred vision at all distances. Only part of what you are looking at is in clear focus at any one time.
See the entire definition of Astigmatism

Autoimmune: Pertaining to autoimmunity, a misdirected immune response that occurs when the immune system goes awry and attacks the body itself.
See the entire definition of Autoimmune

Bullous: Characterized by blistering, such as in a second-degree burn.
See the entire definition of Bullous

Collagen: Collagen is the principal protein of the skin, tendons, cartilage, bone and connective tissue.

Complication: In medicine, an additional problem that arises following a procedure, treatment or illness and is secondary to it. A complication complicates the situation.

Cornea: The clear front window of the eye that transmits and focuses light into the eye.
See the entire definition of Cornea

Corneal: Pertaining to the cornea, the clear front window of the eye that transmits and focuses light into the eye.

Corneal abrasion: A scratch or scrape on the cornea, the clear front window of the eye that transmits and focuses light into the eye.

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Cuts: Severed skin. Washing a cut or scrape with soap and water and keeping it clean and dry is all that is required to care for most wounds. Putting alcohol hydrogen peroxide, and iodine into a wound can delay healing and should be avoided. Seek medical care early if you think that you might need stitches. Any delay can increase the rate of wound infection. Any puncture wound through tennis shoes has a high risk of infection and should be seen by your healthcare professional. Any redness, swelling, increased pain, or pus draining from the wound may indicate an infection that requires professional care.

Diabetes: Refers to diabetes mellitus or, less often, to diabetes insipidus. Diabetes mellitus and diabetes insipidus share the name "diabetes" because they are both conditions characterized by excessive urination (polyuria).
See the entire definition of Diabetes

Diabetic retinopathy: A common complication of diabetes affecting the blood vessels in the retina (the thin light-sensitive membrane that covers the back of the eye). If untreated, it may lead to blindness. If diagnosed and treated promptly, blindness is usually preventable.
See the entire definition of Diabetic retinopathy

Dilation: The process of enlargement, stretching, or expansion. The word "dilatation" means the same thing. Both come from the Latin "dilatare" meaning "to enlarge or expand."

Discharge: 1.The flow of fluid from part of the body, such as from the nose or vagina.
2. The passing of an action potential, such as through a nerve or muscle fiber.
3. The release of a patient from a course of care. The doctor may then dictate a discharge summary.

Dry eye: A deficiency of tears. The main symptom is usually a scratchy or sandy feeling as if something is in the eye. Other symptoms may include stinging or burning of the eye; episodes of excess tearing that follow periods of very dry sensation; a stringy discharge from the eye; and pain and redness of the eye. Sometimes people with dry eye experience heaviness of the eyelids or blurred, changing, or decreased vision, although loss of vision is uncommon.
See the entire definition of Dry eye

Elective: In medicine, something chosen (elected). An elective procedure is one that is chosen (elected) by the patient or physician that is advantageous to the patient but is not urgent.
See the entire definition of Elective

Emergency department: The department of a hospital responsible for the provision of medical and surgical care to patients arriving at the hospital in need of immediate care. Emergency department personnel may also respond to certain situations within the hospital such cardiac arrests.
See the entire definition of Emergency department

Epithelial: Relating to the epithelium, the outside layer of cells that covers all the free, open surfaces of the body including the skin, and mucous membranes that communicate with the outside of the body.

Eyelid: The lid or cover of the eye, a movable fold of skin and muscle that can be closed over the eyeball or opened at will. Each eye has an upper and a lower lid. An eyelid is also called a palpebra.

Farsightedness: Medically termed hyperopia; the ability to see distant objects more clearly than close objects.
See the entire definition of Farsightedness

Focal: Pertaining to a focus which in medicine may refer to:
1. The point at which rays converge as, for example, in the focal point.
2. A localized area of disease. A focal cancer is limited to one specific area.

Glaucoma: A common eye condition in which the fluid pressure inside the eyes rises because of slowed fluid drainage from the eye. If untreated, it may damage the optic nerve and other parts of the eye, causing the loss of vision or even blindness.
See the entire definition of Glaucoma

Herpes: A family of viruses. Herpes also refers to infection with one of the human herpesviruses, especially herpes simplex types 1 and 2.
See the entire definition of Herpes

Hyperopia: Farsightedness; the ability to see distant objects more clearly than close objects.
See the entire definition of Hyperopia back to top

Imitrex: Brand name for sumatriptan, a triptan drug for the treatment of migraine.

Immunosuppressive: 1. Pertaining to immunosuppression, the suppression of the immune system.
2. An agent capable of suppressing the immune response.

In situ: In the normal location. An "in situ" tumor is one that is confined to its site of origin and has not invaded neighboring tissue or gone elsewhere in the body.
See the entire definition of In situ

Infection: The growth of a parasitic organism within the body. (A parasitic organism is one that lives on or in another organism and draws its nourishment therefrom.) A person with an infection has another organism (a "germ") growing within him, drawing its nourishment from the person.
See the entire definition of Infection

Inflammation: A basic way in which the body reacts to infection, irritation or other injury, the key feature being redness, warmth, swelling and pain. Inflammation is now recognized as a type of nonspecific immune response.
See the entire definition of Inflammation

Intraocular: In the eye. The intraocular pressure is the pressure within the eye.

Intraocular lens: An artificial lens made of plastic, silicone, acrylic or other material that is implanted inside the eye during cataract surgery. Abbreviated IOL.
See the entire definition of Intraocular lens

Keloid: A scar that doesn't know when to stop. When the skin is injured, cells grow back to fill in the gap. Somehow, they normally "know" when the scar tissue is level with the skin, at which point the cells stop multiplying. When the cells keep on reproducing, the result is a what is called a overgrown (hypertrophic) scar or a keloid. The result is a keloid -- a tough heaped-up scar that rises quite abruptly above the rest of the skin. It is irregularly shaped and tends to enlarge progressively.
See the entire definition of Keloid

Keratitis: Inflammation of the cornea (the transparent structure in the front of the eye).

Keratoconus: Cone-shaped cornea with the apex of the cone being forward. Also called conical cornea.

Keratoplasty: Corneal transplant.

Keratotomy: A surgical incision (a cut) made into the cornea.
See the entire definition of Keratotomy

Laser: A powerful beam of light that can produce intense heat when focused at close range. Lasers are used in medicine in microsurgery, cauterization, for diagnostic purposes, etc. For example, lasers are employed in microsurgery to cut tissue and remove tissue.
See the entire definition of Laser

LASIK: Abbreviation standing for laser-assisted in situ keratomileusis, a kind of laser eye surgery designed to change the shape of the cornea to eliminate or reduce the need for glasses and contact lenses in cases of severe myopia (nearsightedness).
See the entire definition of LASIK

Lens: The transparent structure inside the eye that focuses light rays onto the retina (the nerve layer that lines the back of the eye, senses light and creates impulses that go through the optic nerve to the brain). The lens was named after the lentil bean because it resembled it in shape and size.
See the entire definition of Lens back to top

Lupus: A chronic inflammatory condition caused by an autoimmune disease. An autoimmune disease occurs when the body's tissues are attacked by its own immune system. Patients with lupus have unusual antibodies in their blood that are targeted against their own body tissues.
See the entire definition of Lupus

Myopia: Nearsightedness, the ability to see close objects more clearly than distant objects.
See the entire definition of Myopia

Nearsightedness: The ability to see near objects more clearly than distant objects. Also called myopia .
See the entire definition of Nearsightedness

NEI: Stands for National Eye Institute, one of the US National Institutes of Health.
See the entire definition of NEI

NIH: The National Institutes of Health. The NIH is an important U.S. health agency. It is devoted to medical research. Administratively under the Department of Health and Human Services (HHS), the NIH consists of 20-some separate Institutes and Centers. NIH's program activities are represented by these Institutes and Centers.
See the entire definition of NIH

Nursing: 1) Profession concerned with the provision of services essential to the maintenance and restoration of health by attending the needs of sick persons. 2) Feeding a infant at the breast.

Ocular: Having to do with the eye.
See the entire definition of Ocular

On call: In medicine, the person who is ready to respond, the one on duty. As in "Who is the doctor on call this weekend?" or "This is the on call schedule."

Operation: Although there are many meanings to the word "operation", in medicine it refers to a surgical procedure.
See the entire definition of Operation

Ophthalmologist: An eye doctor. A physician practicing ophthalmology. An ophthalmologist is an M.D.

Ophthalmology: The art and science of eye medicine.

Outpatient: A patient who is not an inpatient (not hospitalized) but instead is cared for elsewhere -- as in a doctor's office, clinic, or day surgery center. The term outpatient dates back at least to 1715. Outpatient care today is also called ambulatory care.

Pain: An unpleasant sensation that can range from mild, localized discomfort to agony. Pain has both physical and emotional components. The physical part of pain results from nerve stimulation. Pain may be contained to a discrete area, as in an injury, or it can be more diffuse, as in disorders like fibromyalgia. Pain is mediated by specific nerve fibers that carry the pain impulses to the brain where their conscious appreciation may be modified by many factors.
See the entire definition of Pain

Peripheral: Situated away from the center, as opposed to centrally located.
See the entire definition of Peripheral

Pharmacy: A location where prescription drugs are sold. A pharmacy is, by law, constantly supervised by a licensed pharmacist.

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Posterior: The back or behind, as opposed to the anterior.
See the entire definition of Posterior

Postoperative: After surgery. As opposed to preoperative, before surgery.

Pregnant: The state of carrying a developing fetus within the body.
See the entire definition of Pregnant

Presbyopia: The loss of the eye's ability to change focus to see near objects. The reasons for this loss of the power of accommodation are not yet fully known. It is conventionally said to be due to the lens becoming less elastic with time.
See the entire definition of Presbyopia

Prescription: A physician's order for the preparation and administration of a drug or device for a patient. A prescription has several parts. They include the superscription or heading with the symbol "R" or "Rx", which stands for the word recipe (meaning, in Latin, to take); the inscription, which contains the names and quantities of the ingredients; the subscription or directions for compounding the drug; and the signature which is often preceded by the sign "s" standing for signa (Latin for mark), giving the directions to be marked on the container.

Pupil: The opening of the iris. The pupil may appear to open (dilate) and close (constrict) but it is really the iris that is the prime mover; the pupil is merely the absence of iris. The pupil determines how much light is let into the eye. Both pupils are usually of equal size. If they are not, that is termed anisocoria (from "a-", not + "iso", equal + "kore", pupil = not equal pupils).
See the entire definition of Pupil

Radial: A word with diverse meanings in medicine and the biomedical sciences:

  1. Pertaining to the radius, the smaller bone in the forearm. The radial artery is so named because of its proximity to the radius.
  2. Pertaining to the radius of a circle.
  3. Spreading from a central point. A radial keratotomy is an eye operation in which incisions are made in the cornea that resemble the spokes in a wheel.

See the entire definition of Radial

Radial keratotomy: An eye surgery procedure designed to flatten the cornea, reducing its optical power, to correct nearsightedness (myopia). In the procedure, incisions (cuts) are made in the cornea. The procedure is said to be radial because the incisions resemble the spokes in a bicycle wheel.

Refraction: In ophthalmology, the bending of light that takes place within the human eye.
See the entire definition of Refraction

Retina: The retina is the nerve layer that lines the back of the eye, senses light, and creates impulses that travel through the optic nerve to the brain. There is a small area, called the macula, in the retina that contains special light-sensitive cells. The macula allows us to see fine details clearly.
See the entire definition of Retina

Retinal: Pertaining to the retina, the extraordinary layer of neurons (nerve cells) that line the back of the eye, which can sense light and create impulses capable of voyaging through the optic nerve to the brain where the impulses are recognized as an image.
See the entire definition of Retinal

Retinopathy: Any disease of the retina, the light-sensitive membrane at the back of the eye. The type of retinopathy is often specified. Arteriosclerotic retinopathy is retinal disease due to arteriosclerosis ("hardening of the arteries"). Diabetic retinopathy is retinal disease associated with diabetes. Hypertensive retinopathy is retinal disease due to high blood pressure. Etc.

Rheumatoid arthritis: An autoimmune disease which causes chronic inflammation of the joints, the tissue around the joints, as well as other organs in the body. Autoimmune diseases occur when the body tissues are mistakenly attacked by its own immune system. The immune system is a complex organization of cells and antibodies designed normally to "seek and destroy" invaders of the body, particularly infections. Patients with these diseases have antibodies in their blood which target their own body tissues, where they can be associated with inflammation. Because it can affect multiple other organs of the body, rheumatoid arthritis is referred to as a systemic illness and is sometimes called rheumatoid disease. While rheumatoid arthritis is a chronic illness (meaning it can last for years) patients may experience long periods without symptoms.
See the entire definition of Rheumatoid arthritis

Rule out: A term much used in medicine, meaning to eliminate or exclude something from consideration. The ACB (albumin cobalt binding) test helps rule out a heart attack in the differential diagnosis of severe chest pain.

Sensation: In medicine and physiology, sensation refers to the registration of an incoming (afferent) nerve impulse in that part of the brain called the sensorium, which is capable of such perception. Therefore, the awareness of a stimulus as a result of its perception by sensory receptors. (Sensory is here synonymous with sensation.)
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Steroid: A general class of chemical substances that are structurally related to one another and share the same chemical skeleton (a tetracyclic cyclopenta[a]phenanthrene skeleton).
See the entire definition of Steroid

Stroma: The supportive framework of an organ (or gland or other structure), usually composed of connective tissue. The stroma is distinct from the parenchyma, which consists of the key functional elements of that organ. The stroma of the thyroid gland is the connective tissue that supports the lobules and follicles of the thyroid gland.
See the entire definition of Stroma

Superficial: In anatomy, on the surface or shallow. As opposed to deep. The skin is superficial to the muscles. The cornea is on the superficial surface of the eye.
See the entire definition of Superficial

Surgeon: A physician who treats disease, injury, or deformity by operative or manual methods. A medical doctor specialized in the removal of organs, masses and tumors and in doing other procedures using a knife (scalpel). The definition of a "surgeon" has begun to blur in recent years as surgeons have begun to minimize the cutting, employ new technologies that are "minimally invasive," use scopes, etc.
See the entire definition of Surgeon

Surgery: The word "surgery" has multiple meanings. It is the branch of medicine concerned with diseases and conditions which require or are amenable to operative procedures. Surgery is the work done by a surgeon. By analogy, the work of an editor wielding his pen as a scalpel is s form of surgery. A surgery in England (and some other countries) is a physician's or dentist's office.
See the entire definition of Surgery

Tear: A drop of the salty secretion of the lacrimal glands which serves to moisten the conjunctiva and cornea.

Vascular: Relating to the blood vessels of the body. The blood vessels of the body, as a group, are referred to as the vascular system.
See the entire definition of Vascular

Visual acuity: The clarity or clearness of the vision, a measure of how well a person sees. The ability to distinguish details and shapes of objects; also called central vision.
See the entire definition of Visual acuity back to top




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Vision Correction Surgery

Contact Lenses Overview

Contact lenses are miraculous pieces of plastic that allow you to see without glasses. In most cases, contact lenses are used as a substitute for glasses, allowing you to dispense with them. Contact lenses may also be used to treat certain eye diseases or may be used for cosmetic purposes to change the apparent color of your eyes.

Successful contact-lens wear requires a "partnership" between the fitter, that is, an ophthalmologist, an optometrist, or possibly an optician, and you, the wearer.

  • The fitter must first decide if your eyes are healthy enough to wear contact lenses. If so, the fitter then fits the correct lenses for your eyes and your needs and teaches you how to use and care for them.

  • The fitter should be available if problems develop; if not available, the fitter must then have system in place to address those situations.

  • You must follow the instructio...


Read the Contact Lenses article »


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