Presbyopia is a refractive error in which the eye is no longer capable of focusing correctly. It is age related and occurs in all people usually sometime after age 40. Presbyopia is not a disease, although it can make reading and viewing objects up close much more difficult. A comprehensive eye exam can evaluate visual acuity and diagnose presbyopia. Often, patients only require reading glasses to manage the problem, though prescription bifocals, trifocals or contact lenses may be necessary for some people. There are also surgical procedures that can help correct presbyopia.