Cataracts Blurring of Vision

Normal vision requires the natural focusing abilities of the human crystalline lens that is inside the eye. A cataract is the natural clouding of the human crystalline resulting in degradation of acuity and loss of vision.

A cataract is a clouding of the eye's lens that can cause vision problems. The most common type is related to aging. More than half of all Americans age 65 and older have a cataract. In the early stages, stronger lighting and eyeglasses may lessen vision problems caused by cataracts. At a certain point, however, surgery may be needed to improve vision. Today, cataract surgery is generally safe and very effective.

What is a cataract?

The lens is made mostly of water and protein. The protein is arranged to let light pass through and focus on the retina. Sometimes some of the protein clumps together. This can start to cloud small areas of the lens, blocking some light from reaching the retina and interfering with vision. This is a cataract. In its early stages, a cataract may not cause a problem. The cloudiness may affect only a small part of the lens. However, over time, the cataract may grow larger and cloud more of the lens, making it harder to see. Because less light reaches the retina, your vision may become dull and blurry. A cataract won't spread from one eye to the other, although many people develop cataracts in both eyes. Although researchers are learning more about cataracts, no one knows for sure what causes them. Scientists think there may be several causes, including smoking, diabetes, and excessive exposure to sunlight.

What are the symptoms?

The most common symptoms of a cataract are:

• Cloudy or blurry vision.
• Problems with light. These can include headlights that seem too bright at night; glare from lamps or very bright sunlight; or a halo around lights.
• Colors that seem faded.
• Poor night vision.
• Double or multiple vision (this symptom often goes away as the cataract grows).
• Frequent changes in your eyeglasses or contact lenses.

These symptoms can also be a sign of other eye problems. If you have any of these symptoms, check with your eye care professional. When a cataract is small, you may not notice any changes in your vision. Cataracts tend to grow slowly, so vision gets worse gradually. Some people with a cataract find that their close-up vision suddenly improves, but this is temporary. Vision is likely to get worse again as the cataract grows.