Presbyopia
Presbyopia is the physiological and natural evolution of the aging eye.
It is not a refractive disorder, like myopia, hyperopia or astigmatism, but a so-called accommodative disorder. The main symptom of presbyopia is difficulty reading at close range with which eyestrain may be associated after reading or computer activities.
Headache is not uncommon.

As the years go by, the lens gradually hardens and the ciliary muscle, which acts on the lens and regulates accommodation, also weakens, and the eye’s focusing mechanism suffers, making near reading more difficult.
Turning the paper away at the time of reading is surely the most classic example.
Presbyopia begins to occur around age 45 in individuals who do not use glasses (emmetropes), in hypermetropes a little earlier while in myopes the onset delays for a few years.
If you have no other visual defects, it is sufficient to use a pair of near vision glasses to wear when needed, so-called reading glasses.
In case other visual defects coexist, glasses capable of correcting the different deficits should be used. Widely used today are multifocals.