Presbyopia ("over 40")

Everyone is born with a certain amount of focusing ability ("accommodation") in the eyes. Over time, we very gradually lose this ability. The results, for the different conditions are:

• Emmetropic (perfect distance vision) people: their distance vision remains perfect, but now they have a problem seeing closer up.
• Myopic ("nearsighted") people: while wearing their distance eyeglasses, a problem seeing up close. Mildly nearsighed people can usually see fine up close if they take their distance eyeglasses off.
• Hyperopic ("farsighted") people: a problem seeing up close with or without far-away eyeglasses. Eventually even only mild hyperopes frequently need glasses for far away as well as the accommodation gets lower.

Some people are happy with just a pair of eyeglasses for reading-only. Others, who need to change focus from near & far frequently, prefer bifocals or progressive lenses. The reading prescription typically changes every 1-2 years, eventually leveling off after age 60.