Presbyopia occurs because the lens of the eye loses its elasticity, so that the image at the back of the eye is focused in behind the retina rather than onto it when doing close tasks.

Symptoms include having difficulty viewing close objects or small print. Sometimes tired or sore eyes and headaches occur with prolonged concentration on near tasks.

Generally, most people are affected with presbyopia after the age of 40 and it occurs in addition to other visual defects such as shortsightedness, longsightedness and astigmatism.

The correction of presbyopia usually includes the use of spectacles (or sometimes contact lenses) which are worn for close tasks. Both clarity and comfort are improved which results in better visual efficiency. The spectacles come in the form of reading glasses, or for those who already wear spectacles, there are bifocal and progressive lens options. Progressive lenses offer the best solution to presbyopia as they allow the user to enjoy natural vision from far and near in a single pair of spectacles without the distinctive line seen in bifocals.