Astigmatism

Vision condition that occurs when the front surface of your eye, the cornea, is slightly irregular in shape. This irregular shape prevents light from focusing properly on the back of your eye, the retina. As a result, your vision may be blurred at all distances.

Most people have some degree of astigmatism. Almost all levels of can be optically corrected with properly prescribed and fitted eyeglasses or contact lenses.

Blepharitis

Chronic or long-term inflammation of the eyelids and eyelashes that affects people of all ages. Causes include poor eyelid hygiene, excessive oil produced by the glands in the eyelid, bacterial infection (often staphylococcal), or an allergic reaction.

Symptoms are greasy flakes or scales around the base of the eyelashes and a mild redness of the eyelid or a roughness of the normally smooth tissue that lines the inside of the eyelid. In many cases, good eyelid hygiene and a regular cleaning routine may control blepharitis.

Cataract

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. Cataracts may be brought on by 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.

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.

Conjunctivitis

An inflammation of 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, or “pink eye,” caused by a contagious virus or bacteria
• Allergic, the body’s reaction to pollen, cosmetics, animals or fabrics
• Chemical, a response to irritants like air pollution, noxious fumes and chlorine in swimming pools

Symptoms are red watery eyes, inflamed inner eyelids, blurred vision, a scratchy feeling in the eyes and, sometimes, a pus-like or watery discharge. See an optometrist promptly for diagnosis and treatment.

Diabetic retinopathy

A health problem caused by diabetes that 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. The early stages of diabetic retinopathy may cause blurred vision, or they may produce no visual symptoms at all. If left untreated, diabetic retinopathy can cause blindness.

Dry eye

Dry eye means that your eyes do not produce enough tears or that you produce tears that 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.

Dry eye cannot be cured, but your optometrist can prescribe treatment so your eyes remain healthy and your vision is unaffected. In some cases, small plugs are inserted in the corner of the eyes to slow tear drainage.

Farsightedness (hyperopia)

Condition in which distant objects are usually seen clearly, but close ones do not come into proper focus. Farsightedness occurs if your eyeball is too short or the cornea has too little curvature, so light entering your eye is not focused correctly.

Common signs include difficulty in concentrating and maintaining a clear focus on near objects, eye strain, fatigue and headaches after close work, aching or burning eyes, irritability or nervousness after sustained concentration.

Common vision screenings, often done in schools, are generally ineffective in detecting farsightedness. A comprehensive optometric examination will include testing for farsightedness.

Glaucoma

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. 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.

Lazy eye (amblyopia)

The loss or lack of development of central vision in one eye that is unrelated to any eye health problem and is not correctable with lenses. It can result from a failure to use both eyes together. Lazy eye is often associated with crossed-eyes or a large difference in the degree of nearsightedness or farsightedness between the two eyes. It usually develops before the age of six, and it does not affect side vision.

Early diagnosis increases the chance for a complete recovery. This is one reason why the American Optometric Association recommends that children have a comprehensive optometric examination by the age of 6 months and again at age 3. Lazy eye will not go away on its own. If not diagnosed until the pre-teen, teen or adult years, treatment takes longer and is often less effective.

Macular degeneration

The leading cause of blindness in America 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. 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.

Nearsightedness (myopia)

A vision condition in which near objects are seen clearly, but distant objects do not come into proper focus. Nearsightedness occurs if your eyeball is too long or the cornea has too much curvature, so the light entering your eye is not focused correctly.

Nearsightedness is a very common vision condition that affects nearly 30 percent of the U.S. population. Some evidence supports the theory that nearsightedness is hereditary. There is also growing evidence that nearsightedness may be caused by the stress of too much close vision work. It normally first occurs in school-age children. Because the eye continues to grow during childhood, nearsightedness generally develops before age 20.

Presbyopia

A vision condition in which the crystalline lens of your eye loses its flexibility, which makes it difficult for you to focus on close objects.

Presbyopia may seem to occur suddenly, but the actual loss of flexibility takes place over a number of years. Presbyopia usually becomes noticeable in the early to mid-40s. Presbyopia is a natural part of the aging process of the eye. It is not a disease, and it cannot be prevented.

Spots (floaters)

Small, semi-transparent or cloudy specks or particles within the vitreous, which is the clear, jelly-like fluid that fills the inside of your eyes. They appear as specks of various shapes and sizes, threadlike strands or cobwebs. Because they are within your eyes, they move as your eyes move and seem to dart away when you try to look at them directly.

Spots are often caused by small flecks of protein or other matter trapped during the formation of your eyes before birth. They can also result from deterioration of the vitreous fluid, due to aging, or from certain eye diseases or injuries.

By looking in your eyes with special instruments, your optometrist can examine the health of your eyes and determine if what you are seeing is harmless or the symptom of a more serious problem that requires treatment.