Life

Your aging eyes: How you see as time goes by

You may barely notice the changes at first. Maybe you?ve found yourself reaching more often for your glasses to see up close. You might have trouble adjusting to glaring lights or reading when the light is dim. You may even have put on blue socks thinking they were black. These are some of the normal changes to your eyes and vision as you age.


As more Americans head toward retirement and beyond, scientists expect the number of people with age-related eye problems to rise dramatically. You can?t prevent all age-related changes to your eyes. But you can take steps to protect your vision and reduce your risk for serious eye disease in the future. Effective treatments are now available for many disorders that may lead to blindness or visual impairment. You can also learn how to make the most of the vision you have.


?Vision impairment and blindness are among the top five causes of disability in older adults,? says Dr. Cynthia Owsley, an eye researcher at the University of Alabama at Birmingham. Vision changes can make it difficult to perform everyday activities, such as reading the mail, shopping, cooking, walking safely, and driving. ?Losing your vision may not be life-threatening, but it certainly affects your quality of life,? Owsley says.


The clear, curved lens at the front of your eye may be one of the first parts of your body to show signs of age. The lens bends to focus light and form images on the retina at the back of your eye. This flexibility lets you see at different distances?up close or far away. But the lens hardens with age. The change may begin as early as your 20s, but it can come so gradually it may take decades to notice.


Eventually, age-related stiffening and clouding of the lens affects just about everyone. You may have trouble focusing on up-close objects, a condition called presbyopia. Anyone over age 35 is at risk for presbyopia.


?You might find you?re holding your book farther away to read it. You might even start thinking your arms just aren?t long enough,? says Dr. Emily Chew, a clinical researcher at NIH?s National Eye Institute. ?A good and simple treatment for presbyopia is reading glasses.?


Cloudy areas in the lens, called cataracts, are another common eye problem that comes with age. More than 24 million Americans have cataracts. By age 75, more than half of us will have had them. Some cataracts stay small and have little effect on eyesight, but others become large and interfere with vision. Symptoms include blurriness, difficulty seeing well at night, lights that seem too bright and faded color vision. There are no specific steps to prevent cataracts, but tobacco use and exposure to sunlight raise your risk of developing them. Cataract surgery is a safe and common treatment that can restore good vision.


The passage of time can also weaken the tiny muscles that control your eye?s pupil size. The pupil becomes smaller and less responsive to changes in light. That?s why people in their 60s need three times more light for comfortable reading than those in their 20s. Smaller pupils make it more difficult to see at night.


Trouble seeing at night can affect many daily activities, including your ability to drive safely. Loss of peripheral vision increases your risk for automobile accidents, so you need to be more cautious when driving.


?Keeping older adults active and on the road as drivers, as long as they?re safely able to do so, is considered important to their health and psychological well-being,? says Owsley. But she notes that tests for motor vehicle licenses tend to focus on visual acuity?how well you can read the letters on an eye chart.


?Visual acuity tests may not be the best way to identify drivers at risk for crashes,? she says. ?Other issues are also important, like contrast sensitivity, your peripheral vision and your visual processing speed?how quickly you can process visual information and make decisions behind the wheel.?


Owsley and her colleagues measured car crashes among a group of 2,000 drivers, 70 years old and older, over a period of three years. They found that a reduced field of vision and slowed processing speed both increased collision risk. Their research is helping to identify screening tests that can better predict safe or dangerous driving.


If you?re not convinced you should have regular eye exams, consider that some of the more serious age-related eye diseases?like glaucoma, age-related macular degeneration (AMD) and diabetic eye disease?may have no warning signs or symptoms in their early stages.


Glaucoma comes from damage to the optic nerve. ?Glaucoma can slowly steal your peripheral vision. You may not notice it until it?s advanced,? says Chew. It can be treated with prescription eye drops, lasers, or surgery. If not treated, however, it can lead to vision loss and blindness.


AMD causes gradual loss of vision in the center of your eyesight. ?AMD is the leading cause of blindness in Americans over age 65,? says Chew.


A large NIH-supported clinical study by Chew and others found that a specific combination of vitamins and minerals can prevent AMD from progressing to a more severe form. Scientists also found that people who eat diets rich in green, leafy vegetables?such as kale and spinach?or fish are less likely to have advanced AMD. A large study of 4,000 AMD patients failed to show a benefit from fish oil supplements. However, vitamin/mineral supplements?especially those containing lutein and zeaxanthin, which are found in green leafy vegetables?slows progression to vision-threatening late AMD.


Diabetic eye disease, another leading cause of blindness, can damage the tiny blood vessels inside the retina. Keeping your blood sugar under control can help prevent or slow the problem.


The only way to detect these serious eye diseases before they cause vision loss or blindness is through a comprehensive dilated eye exam. Your eye care professional will put drops in your eyes to enlarge, or dilate, the pupils and then look for signs of disease. ?Having regular comprehensive eye care gives your doctor a chance to identify a problem very early on and then treat it,? says Owsley. Annual eye exams are especially important if you have diabetes.


?Many of the healthy behaviors that help reduce your risk for long-term diseases, like heart disease and cancer, can also help to protect your eyesight,? says Owsley. These include not smoking, eating a healthy diet, and controlling conditions like diabetes and high blood pressure. ?It?s nice to know that healthy living not only adds years to your life, but also protects your vision as you get older,? Owsley says.