Vision Problems

What is low vision?

Low vision is decreased vision that cannot be corrected with glasses, contact lenses, medicine, or surgery. People with low vision are not completely blind. However, they have vision problems such as:

• a loss of clear central vision
• a loss of visual field (the area visible around the object that you are looking at directly)
• a loss of color vision
• a loss of the ability to adjust to glare
• a loss of the ability to see well in darkened settings

What is the cause?

Low vision is caused by damage to part of the visual system. The visual system includes the cornea, lens, retina, optic nerve, and vision centers in the brain. The most common causes of low vision are:

• macular degeneration (damage to the center of the retina at the back of the eye)
• diabetic retinopathy (an eye problem caused by diabetes)
• glaucoma (damage to the optic nerve usually caused by high pressure inside the eye)
• optic neuropathy (another type of damage to the optic nerve)
• eye disease you are born with (congenital eye disease)

There are many other causes of low vision.

What are the symptoms?

Symptoms may include:

• trouble reading and seeing small objects
• blurry or spotty vision
• loss of peripheral (side) vision
• loss of depth perception
• the need for bright light most of the time

How is it diagnosed?

Your eye care provider will give you a complete eye exam. He or she will also ask about your medical history because many diseases may affect your eyes.

How is it treated?

Because low vision cannot be treated with ordinary glasses or contact lenses, you will probably use devices to help you with your daily activities. Low-vision aids fit into two broad categories: optical and nonoptical. In addition to these devices, good lighting is important. Learning safety precautions and training in walking or driving with low vision are also important.

What are optical devices and how do they help with low vision?

Optical devices make things look larger. They include:

• Magnifying eyeglasses, which are like regular eyeglasses, but they make things look even larger. With these eyeglasses, you may need to hold your reading material or objects close to your eyes to get it in focus.
• Hand-held magnifiers, which you can buy at drug stores and at low-vision centers. They come in many shapes and sizes.
• Stand magnifiers, so that you do not need to hold anything over your reading material or other objects. They may have their own light source.
• Telescope eyeglasses, which make things at distance look larger than regular glasses do. Each side has two lenses that are separated by a small space.

What are nonoptical devices and how are they used to treat low vision?

Nonoptical devices are tools that can be used easily by people with low vision. Examples are:

• large-number phone keypads
• large-numeral watch faces
• filters to reduce glare
• "talking" clocks or scales
• books, magazines, or newspapers on audio or printed in large type

Many electronic aids can help people with low vision. Some of these are:

• Personal computer hardware and software that enlarge images on a computer screen. These can often be used with closed-circuit TV (CCTV).
• CCTV systems that use video cameras and large TV screens to enlarge reading material, medicine bottles, or pictures.
• Machines that "read" printed material aloud in a computer voice.

Where can people with low vision go for help?

Start with your eye care provider. He or she will recommend treatment or products that may help you. Sometimes your eye care provider will refer you to a low-vision center or specialist for additional help.

Information is also available from many public and private agencies that help people with low vision. You may be eligible for special benefits such as tax relief, phone discounts, and free audio books. Some of these agencies are:

• American Foundation for the Blind
  (1-800-232-5463)
• National Association for the Visually Handicapped
  (1-212-889-3141)
• National Center for Vision and Aging
  (1-800-334-5497)
• National Library Service for the Blind and Physically Handicapped
  Library of Congress
  Washington, DC 20542
  (1-800-424-8567)
• State government agencies for the visually impaired

How can I take care of myself?

Learn what you can about low vision devices that may help you. If you can, try out a product before you buy it. Also, remember the simple things you can do to help you see better:

• Sit close to the TV or hold reading material close to your eyes.
• Use enough light. Even people with no eye problems need about twice as much light at age 60 as they did at age 20 for the same task. Also, wear a visor to block overhead light or special lenses to reduce glare.