As we age, even people who do not have age-related eye diseases and who have good visual acuity may experience vision changes. Presbyopia, which begins in the late 30s or early 40s, usually continues to increase over time. Seniors may also notice:
- Eyes take longer to adjust and focus or don’t adjust very well when a person moves from a well-lit area to a poorly-lit area, or the other way around.
- Such problems in adjusting to light and dark can make driving more difficult, especially at night or in the rain. Driving may be even more challenging for people with eye diseases that reduce their peripheral (side) vision or increase their sensitivity to glare. To be on the safe side, the National Traffic Safety Administration recommends that elders take a driving course designed specifically for seniors, drive during daylight hours, reduce speed and be extra-cautious at intersections.
- It may become more difficult to distinguish an image from its background when subtle gradations of tone are involved. This is called loss of “contrast sensitivity.”
Interestingly, research has found that the eye’s “rod” cells, responsible for the visual functions described above, are more likely to degrade with age than the “cone” cells, which are responsible for visual acuity and color vision. The health of rod cells is also more dependent on environmental factors such as nutrition, smoking, and excessive sun exposure, all of which we can control or choose, to some extent.