By age 45, most of us will need glasses at least for reading. That’s because our eyes’ ability to accommodate—to change focus to see objects at different distances—degrades with age. In young eyes, the eyeball’s crystalline lens changes shape easily, allowing this accommodation. But as we get older, this lens stiffens. Objects in close range suddenly look blurry. Hence the “readers” most middle-aged adults begin wearing on a chain or tucking in a handbag, or the bifocals worn by those who already had vision problems.
Continue reading...
No comments:
Post a Comment