AGE RELATED CHANGES IN EYES AND VISION
All tissues become old with age. The age related changes are usually minimal in the eyes. Changes in the lens lead to lenghtening of the reading distance until one cannot read without glasses. This phenomenon is called presbyopia.
Lens may become cloudy which is called cataract. Also the retina changes with age, some of the capillaries become closed and part of retinal cells die. Changes that occur in the central retina, in the macula, may cause a decrease of visual acuity and contrast sensitivity. Then stronger glasses (with short focus) are needed and one has to read at a shorter reading distance.
It is a common misunderstanding that elderly persons should use their eyes sparingly. Vision does not wear out by being used. Even if there is some decrease of vision it is quite all right to use it as much as is pleasant. If the reading distance is very short the reading posture may be tiring. Therefore it is wise to discontinue reading now and then and move a little around. A few rounds around the arm chair or back and forth to the kitchen increases blood circulation and may make vision clearer for a while. A good reading lamp is a useful aid.
More about old age for colleagues and psychologists.