Presbyopia is a condition in which the lens of the eye loses its ability to focus, making it difficult to see objects close-up.
The condition is associated with aging and gets worse over time. The focusing power of the eye depends on the elasticity of the lens. This elasticity is gradually lost as people age. The result is a slow decrease in the ability of the eye to focus on nearby objects.
People usually notice the condition around age 45, when they realize that they need to hold reading materials further away in order to focus on them. Presbyopia is a natural part of the aging process and affects everyone.