Presbyopia is a gradual loss in the focussing ability (accommodation) of the eye and is part of the normal vision changes we all experience.
This is caused by a natural hardening of the eye lens, so that by the early 40’s it does not respond as well to the muscles intended to change the focus of the eye. As a result, people in this age group start to have difficulty with near tasks like reading small print, threading a needle, etc.. This is especially true at the end of the day when lighting levels are poorer and the individual is more likely to be tired. Correction consists of reading spectacles, bifocals or the newer progressive lenses.