Eye Care Terminology

Amblyopia
Frequently termed ‘lazy eye’, this condition is responsible for loss of vision in more children and young adults than all other ocular diseases combined. A report by the Preschool Children’s Vision Study concludes that “amblyopia, in principle at least, is completely preventable” if risk factors are detected in infancy or early childhood. These risk factors may include undetected refractive errors or muscle weaknesses causing eye turn.
Anterior Uveitis
Anterior uveitis is an inflammation of the middle layer of the eye, which includes the iris (colored part of the eye) and adjacent tissue, known as the ciliary body. If untreated, it can cause permanent damage and loss of vision from the development of glaucoma, cataract or retinal edema. It usually responds well to treatment; however, there may be a tendency for the condition to recur. Treatment usually includes prescription eye drops, which dilate the pupils, in combination with anti-inflammatory drugs. Treatment usually takes several days, or up to several weeks, in some cases.

Anterior uveitis can occur as a result of trauma to the eye, such as a blow or foreign body penetrating the eye. It can also be a complication of other eye disease, or it may be associated with general health problems such as rheumatoid arthritis, rubella and mumps. In most cases, there is no obvious underlying cause.

Signs/symptoms may include a red, sore and inflamed eye, blurring of vision, sensitivity to light and a small pupil. Since the symptoms of anterior uveitis are similar to those of other eye diseases, your optometrist will carefully examine the inside of your eye, under bright light and high magnification, to determine the presence and severity of the condition. Your optometrist may also perform or arrange for other diagnostic tests to help pinpoint the cause.

Astigmatism
Astigmatism blurs vision at all distances because the optical parts of the eye (cornea and lens) do not focus light onto the retina clearly. This condition is quite common, and results from an unequal curve of the cornea when comparing the horizontal and vertical planes. For descriptive purposes, imagine half of a tennis ball, squeezed at the top and bottom; the ball is now curved unequally. In the eye, this results in inaccurate focus on the retina. Lenses are often used to help focus the light to eliminate blurriness from astigmatism.
Blepharitis
Blepharitis is a chronic or long term inflammation of the eyelids and eyelashes. It affects people of all ages. Among the most common causes of blepharitis are poor eyelid hygiene; excessive oil produced by the glands in the eyelid; a bacterial infection (often staphylococcal); or an allergic reaction.

Seborrheic blepharitis is often associated with dandruff of the scalp or skin conditions like acne. It can appear as greasy flakes or scales around the base of the eyelashes and a mild redness of the eyelid. It may also result in a roughness of the normally smooth tissue that lines the inside of the eyelid.

Ulcerative blepharitis is less common, but more serious. It is characterized by matted, hard crusts around the eyelashes, which when removed, leave small sores that ooze or bleed. There may also be a loss of eyelashes, distortion of the front edges of the eyelids and chronic tearing. In severe cases, the cornea, the transparent front covering of the eyeball, may also become inflamed.

In many cases, good eyelid hygiene and a regular cleaning routine may control blepharitis. This includes frequent scalp and face washing; warm soaks of the eyelids; and eyelid scrubs. In cases where bacterial infection is a cause, eyelid hygiene may be combined with various antibiotics and other medications. Eyelid hygiene is especially important upon awakening because debris can build up during sleep.

If you experience symptoms of blepharitis, your doctor of optometry can determine the cause and recommend the right combination of treatments specifically for you.

Cataract
A cataract is a clouding of all or part of the normally clear lens within your eye, which results in blurred or distorted vision.

A cataract is a clouding of all or part of the normally clear lens within your eye, which results in blurred or distorted vision.

A cataract is a clouding of all or part of the normally clear lens within your eye, which results in blurred or distorted vision. Cataracts are most often found in persons over age 55, but they are also occasionally found in younger people.

No one knows exactly what causes cataracts, but it is known that a chemical change occurs within your eye to cause the lens to become cloudy. This may be due to advancing age, heredity or an injury or disease. Excessive exposure to ultraviolet radiation in sunlight, cigarette smoking or the use of certain medications are also risk factors for the development of cataracts.

Although cataracts develop without pain or discomfort, there are some indications that a cataract may be forming. These include blurred or hazy vision, the appearance of spots in front of the eyes, increased sensitivity to glare or the feeling of having a film over the eyes. A temporary improvement in near vision may also indicate formation of a cataract.

Currently, there is no proven method to prevent cataracts from forming. During a comprehensive eye examination, your optometrist can diagnose a cataract and monitor its development and prescribe changes in eyeglasses or contact lenses to maintain good vision.

If your cataract develops to the point that it affects your daily activities, your optometrist can refer you to an eye surgeon who may recommend surgery. During the surgery, the eye’s natural lens is removed and usually replaced with a plastic artificial lens. After surgery, you can return to your optometrist for continuing care.

Cataract Surgery
This procedure typically involves making a small opening in the eye, dissolving and removing the cataract with ultrasound (phacoemulsification) and putting a lens implant in its place. In most cases, the eye is desensitized without injections utilizing topical anesthetic eye drops. Because the opening in the eye is small, it heals rapidly and eliminates the need for stitches in most cases. With this approach, most routine activities can be resumed in a short period of time. Only one eye is operated on at a time. Surgery can generally be performed on the second eye two weeks after the first eye.
Conjunctivitis
Conjunctivitis is an inflammation of the conjunctiva, the thin, transparent layer that lines the inner eyelid and covers the white part of the eye.

The three main types of conjunctivitis are infectious, allergic and chemical. The infectious type, commonly called “pink eye” is caused by a contagious virus or bacteria. Your body’s allergies to pollen, cosmetics, animals or fabrics often bring on allergic conjunctivitis. And, irritants like air pollution, noxious fumes and chlorine in swimming pools may produce the chemical form.

Common symptoms of conjunctivitis are red watery eyes, inflamed inner eyelids, blurred vision, a scratchy feeling in the eyes and, sometimes, a puslike or watery discharge. Conjunctivitis can sometimes develop into something that can harm vision so you should see your optometrist promptly for diagnosis and treatment.

A good way to treat allergic or chemical conjunctivitis is to avoid the cause. If that does not work, prescription or over-the-counter eye drops may relieve discomfort. Infectious conjunctivitis, caused by bacteria, can be treated with antibiotic eye drops. Other forms, caused by viruses, cannot be treated with antibiotics. They must be fought off by your body’s immune system.

To control the spread of infectious conjunctivitis, you should keep your hands away from your eyes, thoroughly wash your hands before applying eye medications and do not share towels, washcloths, cosmetics or eye drops with others.

Cornea
A cornea of the appropriate shape bends (or refracts) incoming light rays so they focus precisely on the retina at the back of the eye.

A cornea of the appropriate shape bends (or refracts) incoming light rays so they focus precisely on the retina at the back of the eye.

The cornea is the clear covering of the front of the eye which bends (or refracts) light rays as they enter the eye. For clear vision to occur, the cornea must have the correct shape and power to focus incoming light rays precisely on the retina at the back of the eye. If the cornea is to steep, too flat or irregular in shape, it cannot bend light at the angle needed to focus on the retina. As a result, eyeglasses or contact lenses may be needed to refract the incoming light rays at the angle needed for clear vision. In a nearsighted eye, for example, the cornea’s shape causes incoming light rays to focus in front of the retina.

In the nearsighted eye, the cornea's shape causes incoming light rays to focus at a point in front of the retina.

In the nearsighted eye, the cornea’s shape causes incoming light rays to focus at a point in front of the retina.

All corneal modification procedures are intended to alter the curvature of the cornea so that incoming light is refracted at an angle that allows it to focus precisely on the retina. This may eliminate the need for eyeglasses or contact lenses, or reduce the power of prescription lenses needed.

Those interested in any of the corneal modifications should first have a comprehensive eye examination to evaluate their eye health and determine their vision needs.

Corneal Topography
A computerized instrument measuring thousands of points on the surface of the cornea. Using these points, a color topographical map detailing the exact curvature and shape of the cornea is created. This allows the doctor to diagnose disease and to prescribe the most accurate contact lens prescription.
Diabetic Retinopathy
Diabetes is a disease that interferes with the body’s ability to use and store sugar and can cause many health problems. One, called diabetic retinopathy, can weaken and cause changes in the small blood vessels that nourish your eye’s retina, the delicate, light sensitive lining of the back of the eye. These blood vessels may begin to leak, swell or develop brush-like branches.

Diabetic Retinopathy is the most common cause of blindness in the United States today.

Blurred side vision may indicate diabetic retinopathy.

The early stages of diabetic retinopathy may cause blurred vision, or they may produce no visual symptoms at all. As the disease progresses, you may notice a cloudiness of vision, blind spots or floaters.

If left untreated, diabetic retinopathy can cause blindness, which is one reason why it is important to have your eyes examined regularly by your doctor of optometry. This is especially true if you are a diabetic or if you have a family history of diabetes.

Diabetic Retinopathy is the most common cause of blindness in the United States today.

Blurred central vision may indicate diabetic retinopathy.

To detect diabetic retinopathy, your optometrist can look inside your eyes with an instrument called an ophthalmoscope that lights and magnifies the blood vessels in your eyes. If you have diabetic retinopathy, laser and other surgical treatments can be used to reduce its progression and decrease the risk of vision loss. Early treatment is important because once damage has occurred, the effects are usually permanent.

If you are a diabetic, you can help prevent diabetic retinopathy by taking your prescribed medication as instructed, sticking to your diet, exercising regularly, controlling high blood pressure and avoiding alcohol and smoking.

November is National Diabetes Month. Members of the American Optometric Association are joining with members of other health care organizations in an effort to prevent blindness in Americans with diabetes. If you or a member of your family has not received a dilated eye examination in the past year, you should contact your optometrist for an appointment. If you do not have an optometrist, call 1-800-262-3947 for the names of doctors in your area.

Learn about treatment for Diabetic Retinopathy.

Dry Eye
The tears your eyes produce are necessary for overall eye health and clear vision. Dry eye means that your eyes do not produce enough tears or that you produce tears which do not have the proper chemical composition. Often, dry eye is part of the natural aging process. It can also be caused by blinking or eyelid problems, medications like antihistamines, oral contraceptives and antidepressants, a dry climate, wind and dust, general health problems like arthritis or Sjogren’s syndrome and chemical or thermal burns to your eyes.

If you have dry eye, your symptoms may include irritated, scratchy, dry, uncomfortable or red eyes, a burning sensation or feeling of something foreign in your eyes and blurred vision. Excessive dry eyes may damage eye tissue, scar your cornea (the front covering of your eyes) and impair vision and make contact lens wear difficult.

If you have symptoms of dry eye, see your optometrist for a comprehensive examination. Dry eye cannot be cured, but your optometrist can prescribe treatment so your eyes remain healthy and your vision is unaffected. Some treatments that your optometrist might prescribe include blinking more frequently, increasing humidity at home or work, using artificial tears and using a moisturizing ointment, especially at bedtime. In some cases, small plugs are inserted in the corner of the eyes to slow tear drainage. Sometimes, surgical closure of the drainage ducts may be recommended.

Glaucoma
Glaucoma is an eye disease in which the internal pressure in your eyes increases enough to damage the nerve fibers in your optic nerve and cause vision loss. The increase in pressure happens when the passages that normally allow fluid in your eyes to drain become clogged or blocked. The reasons that the passages become blocked are not known.

Glaucoma is one of the leading causes of blindness in the U.S. It most often occurs in people over age 40. People with a family history of glaucoma, African Americans, and those who are very nearsighted or diabetic are at a higher risk of developing the disease.

The most common type of glaucoma develops gradually and painlessly, without symptoms. A rarer type occurs rapidly and its symptoms may include blurred vision, loss of side vision, seeing colored rings around lights and pain or redness in the eyes.

Glaucoma cannot be prevented, but if diagnosed and treated early, it can be controlled. Vision lost to glaucoma cannot be restored. That is why the American Optometric Association recommends annual eye examinations for people at risk for glaucoma (your doctor may, depending on your condition, recommend more frequent examinations). Learn more about Glaucoma detection, management, and treatment.

Heidelberg Retinal Tomography
Representing the most current advancement in the management of glaucoma, the HRT allows doctors to image the optic nerve. Repeated over time, these optic nerve images are precisely measured. Fine changes to the tissue of the nerve are detected by the instrument, thus monitoring even the slightest advancement of the disease. This allows the doctor to prescribe a treatment regimen most efficacious to the patient.
Hyperopia
Often called farsightedness, hyperopia is when the eyeball is too short for the normal focusing power of the eye. Depending on severity, it can cause blurred vision, eye fatigue and sometimes amblyopia or crossed eyes.
Keratoconus
Keratoconus is a vision disorder that occurs when the normally round cornea (the front part of the eye) becomes thin and irregular (cone) shaped. This abnormal shape prevents the light entering the eye from being focused correctly on the retina and causes distortion of vision.

Keratoconus is a vision disorder that occurs when the normally round cornea (the front part of the eye) becomes thin and irregular (cone) shaped.

Keratoconus is a vision disorder that occurs when the normally round cornea (the front part of the eye) becomes thin and irregular (cone) shaped.

In its earliest stages, keratoconus causes slight blurring and distortion of vision and increased sensitivity to glare and light. These symptoms usually appear in the late teens or late twenties. Keratoconus may progress for 10-20 years and then slow in its progression. Each eye may be affected differently. As keratoconus progresses, the cornea bulges more and vision may become more distorted. In a small number of cases, the cornea will swell and cause a sudden and significant decrease in vision. The swelling occurs when the strain of the cornea’s protruding cone-like shape causes a tiny crack to develop. The swelling may last for weeks or months as the crack heals and is gradually replaced by scar tissue. If this sudden swelling does occur, your doctor can prescribe eye drops for temporary relief, but there are no medicines that can prevent the disorder from progressing.

Eyeglasses or soft contact lenses may be used to correct the mild nearsightedness and astigmatism that is caused by the early stages for keratoconus. As the disorder progresses and cornea continues to thin and change shape, rigid gas permeable contact lenses can be prescribed to correct vision adequately. In most cases, this is adequate. The contact lenses must be carefully fitted, and frequent checkups and lens changes may be needed to achieve and maintain good vision.

Macular Degeneration
Macular degeneration is the leading cause of blindness in America. It results from changes to the macula, a portion of the retina that is responsible for clear, sharp vision and is located at the back of the eye.

Macular Degeneration: example of the loss of central vision which a patient with macular degeneration may suffer

As macular degeneration advances, a distorted, dark, or empty area often appears in the center of vision.

Most people with macular degeneration have the dry form, for which there is no known treatment. The less common wet form may respond to laser procedures, if diagnosed and treated early.

Some common symptoms are a gradual loss of ability to see objects clearly, distorted vision, a gradual loss of color vision and a dark or empty area appearing in the center of vision.

If you experience any of these, contact your doctor of optometry immediately for a comprehensive examination.

Central vision that is lost to macular degeneration cannot be restored. However, low vision devices such as telescopic and microscopic lenses can be prescribed to make the most out of remaining vision.

Recent research indicates certain vitamins and minerals may help prevent or slow the progression of macular degeneration. Ask your doctor of optometry about these. After age 60, an annual, comprehensive eye examination is an important to maintain eye health.

Learn about management and treatment for Macular Degeneration.

Myopia
Often called nearsightedness, myopia causes distant objects to appear blurred. The eyeball is too long for the normal focusing power of the eye.
Ocular Hypertension
Ocular hypertension is an increase in the pressure in your eyes that is above the range considered normal with no detectable changes in vision or damage to the structure of your eyes. The term is used to distinguish people with elevated pressure from those with glaucoma, a serious eye disease that causes damage to the optic nerve and vision loss.

Ocular hypertension can occur in people of all ages, but it occurs more frequently in African Americans, those over age 40 and those with family histories of ocular hypertension and/or glaucoma. It is also more common in those who are very nearsighted or who have diabetes.

Ocular hypertension has no noticeable signs or symptoms. Your doctor of optometry can check the pressure in your eyes with an instrument called a tonometer and can examine the inner structures of your eyes to assess your overall eye health.

Not all people with ocular hypertension will develop glaucoma. However, there is an increased risk of glaucoma among those with ocular hypertension, so regular comprehensive optometric examinations are essential to your overall eye health.

There is no cure for ocular hypertension, however, careful monitoring and treatment, when indicated, can decrease the risk of damage to your eyes.

Optometrist:
American Optometric Association doctors of optometry are highly qualified, trained doctors, on the frontline of eye health and vision care, who examine, diagnose, treat, and manage diseases and disorders of the eye. In addition to providing eye and vision care, optometrists play a major role in an individual’s overall health and well-being by appropriately detecting systemic diseases. Doctors of optometry provide more than two-thirds of all primary eye care in the United States. The American Optometric Association represents more than 33,000 doctors of optometry, optometry students and paraoptometric assistants and technicians in nearly 6,500 communities across the country.  For more information, visit www.aoa.org.
Ortho-K
Ortho-K is a non-surgical procedure that involves the wearing of a series of specially designed rigid contact lenses to progressively reshape the curvature of the cornea over time. The results of the painless procedure are not permanent; thus, retainer contact lenses must be worn periodically to maintain improvements made in vision. Ortho-K is used to treat low to moderate nearsightedness and low degrees of astigmatism.
Retinitis Pigmentosa (RP)
Retinitis pigmentosa (RP) is a group of inherited diseases that damage the light-sensitive rods and cones located in the retina, the back part of our eyes. Rods, which provide side (peripheral) and night vision are affected more than the cones which provide color and clear central vision.

The first sign of Retinitis Pigmentosa (RP) is often night blindness followed by a slow loss of side vision.

The first sign of Retinitis Pigmentosa (RP) is often night blindness followed by a slow loss of side vision.

Signs of RP usually appear during childhood or adolescence. The first sign is often night blindness followed by a slow loss of side vision. Over the years, the disease will cause further loss of side vision. As the disease develops, people with RP may often bump into chairs and other objects as side vision worsens and they only see in one direction – straight ahead. They see as if they are in a tunnel (thus the term tunnel vision).

Fortunately, most cases of retinitis pigmentosa take a long time to develop and vision loss is gradual. It may take many years for loss of vision to be severe.

Currently, there is no cure for RP, but there is research that indicates that vitamin A and lutein may slow the rate at which the disease progresses. Your doctor of optometry can give you more specific information on nutritional supplements that may help you.

Also, there are many new low vision aids, including telescopic and magnifying lenses, night vision scopes as well as other adaptive devices, that are available that help people maximize the vision that they have remaining. An optometrist, experienced in low vision rehabilitation, can provide these devices as well as advice about other training and assistance to help people remain independent and productive.

Since it is an inherited disease, research into genetics may one day provide a prevention or cure for those who have RP.

Selective Laser Trabeculoplasty (SLT)

This procedure is most often used as an additive therapy for glaucoma treatment, and is commonly recommended after two or three topical medications have been prescribed and the disease is still progressing. SLT represents the most current technological advance in glaucoma treatment. It was approved by the Federal Drug Administration (FDA) in 2001.

The procedure works by creating a mechanical transformation of the tissue in the trabecular meshwork of the eye. The laser treatment produces heat and energy in this area, which in turn increases spacing and causes a greater outflow of the fluid within the eye. This increased fluid outflow lowers the intraocular pressure of the eye. Typically, patients diagnosed with primary open-angle glaucoma (nearly 80% of all glaucoma cases) respond favorably to SLT.

At the time of SLT, the patient undergoes topical anesthesia. After the procedure, patients are typically monitored for 1-2 hours to rule out complications. Following a normal procedure, the patient is seen back for follow-up in one week.

Strabismus
Strabismus occurs when one eye does not aim at the same object being viewed as the other eye. The “eye turn” may be present continuously or only occasionally, and the turn may be inward toward the nose (esotropia) or outward (exotropia), up or down. There is a common misconception that a child will outgrow crossed-eyes. This is not true. Untreated, this condition can lead to amblyopia.
Visian Lens Implant
This refractive surgical procedure is available for patients not eligible for LASIK due to thin corneal tissue, or high myopic corrections. During the procedure, a contact-like lens is placed inside the eye over the pupil to permanently correct the patient’s refraction. The lens redirects light rays entering the eye to allow better focus on the retina. The lens is smaller than a contact lens, and is invisible once inside the eye.