Presbyopia: prevalence, impact, and interventions.

Presbyopia is an age-related loss of lens accommodation that results in an inability to focus at near distances. It is the most common physiological change occurring in the adult eye and is thought to cause universal near vision impairment with advancing age. People who become presbyopic may complain of headaches and eye strain, and hold objects progressively further away from their eyes in order to be able to focus on them. However, while objects may then be in focus, they may become too small to be identified. The length of the arm also limits this compensatory mechanism. The most common remedy is the prescription of a pair of reading spectacles. It is now increasingly recognised that presbyopia is an aspect of refractive error that needs to be addressed. Good near vision is important, even among populations who use it for tasks other than reading and writing.