Presbyopia
Presbyopia is a condition in which the eyes are not able to focus on near objects. This usually happens around age 40, when the eye begins to lose its ability to change the shape of the lens so it can focus on near objects (accommodation).
Presbyopia is a normal part of aging that affects most people. Besides a decreased ability to focus on near objects, symptoms include eyestrain and headaches.
Glasses or contact lenses usually can improve this condition. As the ability to focus up close gets worse, the prescription needs to be changed. Surgery may also help some people.