Presbyopia

Also known as: Age-related farsightedness

The progressive loss of near focus that begins in the early forties, caused by stiffening of the eye's lens and ciliary apparatus.

Presbyopia is universal — everyone develops it, typically starting between 40 and 45 years of age, because the crystalline lens loses elasticity and the ciliary muscle weakens. The result is difficulty focusing on close objects, especially in low light. Reading glasses, bifocals, progressives, or contact lenses correct it. Presbyopia also amplifies digital eye strain: the lens cannot accommodate as effectively, so the same screen hours produce more end-of-day fatigue. Regular breaks become more important after 45.