Select a letter from the alphabet below to find the Eye Disease or select "All" to view the entire list of diseases.

A - B - C - D - E - F - G - H - I - J - K - L - M - N
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C

Cataract

Description:A cataract is a cloudy or opaque area in the lens of the eye. The lens of an eye is normally clear. If the lens becomes cloudy, the condition is known as a cataract. Rarely, cataracts may be present at or shortly after birth. These are called congenital cataracts.

Cause:Adult cataracts usually develop with advancing age and may run in families. Cataracts are accelerated by environmental factors, such as smoking or exposure to other toxic substances, or they may develop at any time after an eye injury. Metabolic diseases such as diabetes also greatly increase the risk for cataracts. Certain medications, such as cortisone, can also accelerate cataract formation. Congenital cataracts may be inherited. The gene for such cataracts is dominant (autosomal dominant inheritance), which means that the defective gene will cause the condition even if only one parent passes it along. Approximately 50% of children in such families will be affected.Congenital cataracts can also be caused by infections of the mother during pregnancy such as rubella, or associated with metabolic disorders such as galactosemia. Risk factors include inherited metabolic diseases, a family history of cataracts, and maternal viral infection.

Treatment:The only treatment for cataract is surgical removal. This is done when a person cannot see well enough with glasses to perform normal activities. For some people, changing glasses, getting stronger bifocals, or using a magnifying lens is helpful enough. Others choose to have cataract surgery. If a cataract is not bothersome, then surgery is usually not necessary. Sometimes there is an additional eye problem that cannot be treated without first proceeding with cataract surgery. Cataract surgery consists of removing the lens of the eye and replacing it with an artificial lens. For most people, cataract surgery has a low risk of complications. With implanted artificial lenses, most people no longer need corrective lenses for distance vision. Glasses are usually necessary for reading. Vision may not improve to 20/20 after cataract surgery if other eye diseases such as macular degeneration are present. In infants, amblyopia and decreased visual development may occur as a result of cataracts. Early diagnosis and treatment is essential.

CMV Retinitis

Description:Cytomegalovirus (CMV) retinitis is a sight-threatening disease associated with late-stage AIDS. When CMV invades the retina, it begins to compromise the light-sensitive receptors that enable us to see. This does not cause any pain, but you may see floaters or small specks, and experience decreased visual acuity (blurry vision) or decreased peripheral vision. The disease usually starts in one eye, but often involves both eyes. If left untreated, CMV retinitis can cause retinal detachment and blindness within two to six months.

Cause:CMV retinitis is caused by the cytomegalovirus, a very common virus: about 80% of adults harbor antibodies to CMV, which indicates their bodies have successfully fought it off. The difference for people who have AIDS is that their weakened or non-functioning immune system cannot stave off this virus.

Treatment:For those with active AIDS and experiencing visual symptoms should see a retina specialist immediately. The drugs commonly used to treat CMV retinitis are ganciclovir (Cytovene), foscarnet (Foscavir) and cidofovir (Vistide). They can slow down the progression of CMV, but they can't cure it.

Color Blindness

Description:Color blindness is not a form of blindness at all, but a deficiency in the way one sees color. With this vision problem, there is difficulty distinguishing certain colors, such as red and green or blue and yellow. Red-green color deficiency is the most common form of color blindness; a less common form is blue-yellow color deficiency.

Cause:Color blindness occurs when certain cells in the retina that normally respond to color do not respond as they should. Usually, people with a color deficiency are born with it, and the problem affects more men than it does women. Color blindness is caused by a common X-linked recessive gene. This means that if you're color-blind, your mother must either be color-blind, or have normal vision but carry the color-deficient gene. Color-blind fathers pass the gene to their daughters only, who will have normal color vision unless their mother also carries the color-deficient gene. Aging or disease can also damage retinal cells, and in extreme cases can lead to almost total color blindness.

Treatment:Color blindness cannot be cured. However, if you have difficulty distinguishing colors, or you've observed this difficulty in your child, see your eyecare practitioner. Some people use special lenses for color blindness, which are filters available in either contact lens or eyeglass lens form. One can also learn ways to work around the inability to pick out certain colors.

Computer Vision Syndrome

Description:Computer vision syndrome (CVS) is a term that describes eye-related problems and the other symptoms caused by prolonged computer use. As our dependence on computers continues to grow, an increasing number of people are seeking medical attention for eye strain and irritation, along with back, neck, shoulder, and wrist soreness.

Cause:CVS is caused by our eyes and brain reacting differently to characters on the screen than they do to printed characters. Our eyes have little problem focusing on most printed material, which is characterized by dense black characters with well-defined edges. Healthy eyes can easily maintain focus on the printed page. Characters on a computer screen, however, don't have this contrast or well-defined edges. These characters (pixels) are brightest at the center and diminish in intensity toward their edges. This makes it very difficult for our eyes to maintain focus and remain fixed onto these images. Instead our eyes drift out to a point called the "resting point of accommodation" or RPA and then strain to regain focus on the screen. This continuous flexing of the eyes' focusing muscles creates fatigue and the burning, tired-eyes feeling that is so common after long hours at the computer.

Treatment:See an eyecare professional that specializes in computer vision care. In most cases, standard reading glasses or over-the-counter readers are not accurate enough, because viewing a computer is usually at a different distance (18"-28") than reading distance (16"-21"). Once an eye doctor accurately diagnoses your computer vision problem and determines your correct computer working distances, it's a simple matter to prescribe computer eyeglasses that will allow you to work comfortably and productively.

Conjunctivitis

Description:Conjunctivitis, commonly known as pink eye, is an infection of the conjunctiva (the thin, transparent layer that lines the inner eyelid and covers the white part of the eye). The three most common types of conjunctivitis are: viral, allergic, and bacterial. Each requires different treatments. With the exception of the allergic type, conjunctivitis is typically contagious.

Cause:The viral type is often associated with an upper respiratory tract infection, cold, or sore throat. The allergic type occurs more frequently among those with allergic conditions. When related to allergies, the symptoms are often seasonal. Allergic conjunctivitis may also be caused by intolerance to substances such as cosmetics, perfume, or drugs. Bacterial conjunctivitis is often caused by bacteria such as staphylococcus and streptococcus. The severity of the infection depends on the type of bacteria involved.

Treatment:Conjunctivitis requires medical attention. The appropriate treatment depends on the cause of the problem. For the allergic type, cool compresses and artificial tears sometimes relieve discomfort in mild cases. In more severe cases, non-steroidal anti-inflammatory medications and antihistamines may be prescribed. Some patients with persistent allergic conjunctivitis may also require topical steroid drops. Bacterial conjunctivitis is usually treated with antibiotic eye drops or ointments that cover a broad range of bacteria. There is no cure for viral conjunctivitis; however, the symptoms can be relieved with cool compresses and artificial tears. For the worst cases, topical steroid drops may be prescribed to reduce the discomfort from inflammation.

Corneal Ulcer

Description:A corneal ulcer forms when the surface of the cornea is damaged or compromised. Ulcers may be sterile (no infecting organisms) or infectious. The term infiltrate is also commonly used along with ulcer. Infiltrate refers to an immune response causing an accumulation of cells or fluid in an area of the body where they don't normally belong.

Cause:There are many causes of corneal ulcers. Contact lens wearers (especially soft) have an increased risk of ulcers if they do not adhere to strict regimens for the cleaning, handling, and disinfection of their lenses and cases. Soft contact lenses are designed to have very high water content and can easily absorb bacteria and infecting organisms if not cared for properly. Pseudomonas is a common cause of corneal ulcer seen in those who wear contacts. Bacterial ulcers may be associated with diseases that compromise the corneal surface, creating a window of opportunity for organisms to infect the cornea. Patients with severely dry eyes, difficulty blinking, or are unable to care for themselves, are also at risk. Other causes of ulcers include: herpes simplex viral infections, inflammatory diseases, corneal abrasions or injuries, and other systemic diseases.

Treatment:The course of treatment depends on whether the ulcer is sterile or infectious. Bacterial ulcers require aggressive treatment. In some cases, antibacterial eye drops are used every 15 minutes. Steroid medications are avoided in cases of infectious ulcers. Some patients with severe ulcers may require hospitalization for IV antibiotics and around-the-clock therapy. Sterile ulcers are typically treated by reducing the eye's inflammatory response with steroid drops, anti-inflammatory drops, and antibiotics.

Cystoid Macular Edema

Description:Cystoid macular edema (CME) is swelling of the macula.

Cause:This typically occurs as a result of disease, injury or more rarely, eye surgery. Fluid collects within the layers of the macula, causing blurred, distorted central vision. CME rarely causes a permanent loss of vision, but the recovery is often a slow, gradual process.

Treatment:The first line of treatment for CME is usually anti-inflammatory drops. In certain cases, medication is injected near the back of the eye for a more concentrated effect. Oral medications are sometimes prescribed to reduce the swelling.