Presbyopia is an age-related impairment of near vision. To see clear images, eye must focus light and it has two structures to do this – the cornea and the lens. The cornea does about 60 percent of focusing and the lens fine-tunes with about 40 percent. Together, in a 20/20 eye, they focus images on the retina regardless of how near or distant an object is.
What Causes Presbyopia ?