Presbyopia

Presbyopia is the main condition that affects the human eye with age. This condition usually begins anywhere between the late thirties and the early fifties, depending on a person’s refractive error, specific visual needs and the health of the eyes.

The crystalline lens inside the eye, which contributes about a quarter of the focussing power of the eye, is responsible for accommodation (the ability to focus clearly at different distances from the eyes). In very young children, the crystalline lens is extremely flexible so that a child may be able to focus on an object just a few centimetres from the eye. Over the first six to eight decades of life, the lens gradually hardens, eventually behaving like a lump of optical rock, and this hardening process causes the eye to become less efficient in changing focus from one distance to another