In some cases, macular degeneration advances so slowly that people notice little change in their vision. In others, the disease progresses faster and may lead to a loss of vision in both eyes. Macular degeneration is a leading cause of vision loss in Americans 60 years of age and older.

The macula is located in the center of the retina, the light-sensitive tissue at the back of the eye. The retina instantly converts light, or an image, into electrical impulses. The retina then sends these impulses, or nerve signals, to the brain.

Wet macular degeneration occurs when abnormal blood vessels behind the retina start to grow under the macula. These new blood vessels tend to be very fragile and often leak blood and fluid. The blood and fluid raise the macula from its normal place at the back of the eye. Damage to the macula occurs rapidly.

With wet macular degeneration, loss of central vision can occur quickly. Wet macular degeneration is also known as advanced macular degeneration. It does not have stages like dry macular degeneration.

An early symptom of wet macular degeneration is that straight lines appear wavy. If you notice this condition or other changes to your vision, contact your eye care professional at once. You need a comprehensive dilated eye exam.

Dry macular degeneration occurs when the light-sensitive cells in the macula slowly break down, gradually blurring central vision in the affected eye. As dry macular degeneration gets worse, you may see a blurred spot in the center of your vision. Over time, as less of the macula functions, central vision is gradually lost in the affected eye.

The most common symptom of dry macular degeneration is slightly blurred vision. You may have difficulty recognizing faces. You may need more light for reading and other tasks. Dry macular degeneration generally affects both eyes, but vision can be lost in one eye while the other eye seems unaffected.

One of the most common early signs of dry macular degeneration is drusen.Drusen are yellow deposits under the retina. They often are found in people over age 60. Your eye care professional can detect drusen during a comprehensive dilated eye exam.

Drusen alone do not usually cause vision loss. In fact, scientists are unclear about the connection between drusen and macular degeneration. They do know that an increase in the size or number of drusen raises a person's risk of developing either advanced dry macular degeneration or wet macular degeneration. These changes can cause serious vision loss.

Both dry and wet macular degeneration cause no pain.

For dry macular degeneration: the most common early sign is blurred vision. As fewer cells in the macula are able to function, people will see details less clearly in front of them, such as faces or words in a book. Often this blurred vision will go away in brighter light. If the loss of these light-sensing cells becomes great, people may see a small--but growing--blind spot in the middle of their field of vision.

For wet macular degeneration: the classic early symptom is that straight lines appear crooked. This results when fluid from the leaking blood vessels gathers and lifts the macula, distorting vision. A small blind spot may also appear in wet macular degeneration, resulting in loss of one's central vision.