Presbyopia is an age-related condition that causes blurred near vision. It typically starts at around age 40 and affects everyone, even those who've never had vision problems before.
When presbyopia begins, people will squint or hold reading materials at arm's length to help their eyes focus. Eye strain, headache and fatigue are common symptoms of presbyopia.
Most experts believe presbyopia is caused by changes to the lens inside the eye. As people age, the lens becomes harder and less elastic, making it more difficult for the eye to focus on close objects.
For centuries presbyopia was corrected with the use of bifocal eyeglasses. Presbyopia can be corrected with eyeglasses, contact lenses, or surgery.