Presbyopia (literally 'old eye' in Greek) is the age-related, progressive loss of accommodative amplitude—the ability of the eye to change focus from distant to near targets. The lens of the human eye is normally able to flex and increase its curvature in response to ciliary muscle contraction, increasing its refractive power for near vision. With aging, the lens progressively hardens (lenticular sclerosis) and the lens substance increases in density, while the ciliary muscle and zonular fibers also undergo changes. Together, these changes reduce accommodative amplitude from approximately 14-15 diopters at age 8 to less than 1 diopter by age 60.
Symptoms typically begin around age 40-45 with difficulty reading small print, especially in low light, requiring increased reading distance ('arms too short'). Other symptoms include eye strain, headaches with prolonged reading or near work, blurred near vision after extended computer use, and difficulty transitioning between near and distant tasks. Symptoms worsen progressively until the mid-60s when accommodation is essentially absent. Hyperopic individuals develop symptoms earlier than emmetropic patients, while myopic individuals (-3.00 D or greater) may delay reading glasses by removing distance correction. Population studies indicate that 1.8 billion people globally have presbyopia, with 826 million experiencing functional impairment without correction.
Optical management options include reading glasses (single-vision near correction, simplest approach), bifocals (separate distance and near zones with distinct line), progressive addition lenses or PALs (smooth transition from distance to near, most cosmetic), occupational lenses (computer-specific designs), and contact lens approaches (multifocal contacts with concentric or aspheric designs, monovision with one eye corrected for distance and the other for near). Surgical management has expanded significantly: refractive lens exchange with multifocal IOLs (trifocal designs like AT LISA tri, PanOptix), extended depth of focus IOLs (Symfony, Vivity), accommodating IOLs, and small aperture IOLs (IC-8 Apthera). Corneal-based options include corneal inlays (KAMRA, Raindrop) though some have been withdrawn, presbyLASIK with multifocal corneal ablation, and conductive keratoplasty. Pharmacologic management has emerged with pilocarpine 1.25% (Vuity, FDA-approved 2021) producing pupillary constriction and increased depth of focus. Other miotic agents in development include aceclidine and pilocarpine combinations.