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Age-Related Vision Changes: What to Expect
Vision changes as we age are only to be expected. Vision changes require adjustments, but relatively few age-related eye conditions result in permanent loss of sight. Instead, the changes in vision that occur as we get older are more likely to be considered an unavoidable nuisance, something we may not want to deal with, but we must. One of the least-noticed changes in vision with aging is loss of pupil size. The pupil is that black spot in the center of the eye that muscles make wider or narrower to let in more or less light. Widening the pupils at night allows for better night vision. By age 60, however, most of us have pupils that just don't move as wide or as quickly as they used to. The eye receives only 1/3 as much ambient light at age 60 as it does at age 20. This means that people over 60 need 3 times as much light to read as they did at age 20. It also means that people over 60 are more likely to be temporarily "blinded" when they go from a brightly lit place to a dark place, such as going inside a theater or a windowless meeting room on a sunny day. And because your pupils' muscles don't close quickly when you go back out into bright light, glare can be just as big a problem. There is not a lot you can do about the need for stronger illumination except to turn on more lights or, when you can't, to use your brain and plan ahead. For the vision changes caused by moving from a dark area to a bright area, however, you can use glasses with photochromic lenses or anti-reflective coatings. Another nearly universal vision change taking place by age 60 is presbyopia, better known as farsightedness. As we age, the material in the center of the lens gets harder, and images of nearby objects focus in front of the retina. This means that we may actually see distant objects better, but reading and any kind of work or play requiring eye-hand coordination become more difficult. Fortunately, farsightedness is not hard to correct. Millions of people buy bifocals, trifocals, and other multifocal lenses in eyeglasses and contact lenses, and, after a few days of getting adjusted to the lenses, normal vision is restored. Farsightedness, however, is a progressive condition, and a different lens prescription may be needed every year or two. There are also surgical procedures (Lasik and conductive keratoplasty) to correct farsightedness, just as there are surgical procedures to correct nearsightedness. Aging also affects the eyes' ability to distinguish shades of the basic colors. The cells in the retina that distinguish color are less likely as we age, and blue colors are especially likely to fade out. There is no treatment for the condition, but it is possible to arrange activities so that color perception is not as critical.
Aging eyes Finally, we all experience peripheral vision changes we age. The ability to see objects up and down and to the sides deteriorates 1 or 2% a year after age 40, so that by age 70 it's not unusual to have lost 30% of peripheral vision, or more. There are no medical treatments for this "normal" condition of aging, but remembering to clear traffic and turning the head to the side when walking can prevent accidents and injuries. |