A cataract is a clouding of the lens in the eye. The normal lens is clear and focuses light so we can see clear images.

Inside your eye, the lens is contained in a capsule. As old cells die they become trapped within the capsule. Over time, more cells die and accumulate causing the lens to cloud. This makes images look blurred or fuzzy.

Cataracts are a common cause of poor vision and a natural result of aging. But, eye injuries, certain medications, and diseases such as diabetes and alcoholism may also cause cataracts.

In the early stages of cataracts, stronger lighting and a change in eyeglasses may help you to see better.

At a certain point, however, surgery may be needed to replace a clouded lens with an artificial one to improve your vision. Cataract surgery is the most frequently performed surgery in the United States. More than 90 percent of the people who have cataract surgery regain useful vision.

Symptoms that may occur if you have a cataract:

• Blurry vision, with no pain
• Glare, or sensitivity to light
• Many eyeglass prescription changes
• Double vision in one eye
• A need to read with a bright light
• Poor vision at night
• Dull or yellowed color

To find out whether you have a cataract or other eye problems, see an eye doctor for a complete eye exam.

Source: Eye Care America, Foundation of the American Academy of Ophthalmology, www.eyecareamerica.org.