It is an alteration of near vision that typically appears after the age of 40, and that in the case of latent hyperopic patients can also end up affecting distance vision. It is due to a progressive deterioration of the lens, which loses its ability to accommodate when it loses its flexibility.

This process of deterioration of the lens, normal with age, is the same that later leads to the appearance of a cataract 20 or 30 years later.