Presbyopia

(loss of accommodation) When the natural lens of the eye becomes less flexible with age, the eye is unable to focus on small objects close up. This loss of accommodation is called prebyopia and is accompanied by blurred near vision.

Dear Mid-Life Crisis,

Relax, the sky is not falling; your eyes are probably just undergoing normal changes due to middle age... The lens inside the eye was very flexible when you were younger, allowing the muscle inside the eye to automatically alter its shape when you focused on anything close to you... Now, that lens is stiffening, so you will most likely need to wear a convex lens (Either in glasses or as a contact lens) when you read small print.

The condition of "Presbyopia" (Translated literally it means "old eye") can be compensated for by either single vision reading glasses or bifocals. The types of bifocals include several versions of the same lined lenses invented by Benjamin Franklin, as well as the newer "Progressive addition" lenses that have no lines.