Abstract

Ocular accommodation describes the neuromuscular process that allows the eye to focus clearly objects located at distances from infinity to a near point determined by the amplitude of accommodation and is a reflex response that appears to occur instantaneously in prepresbyopic individuals. ¹ Objects continue to appear clear when attention is altered from one object to another even when a significant increase in ocular accommodation is required.² Increases in accommodation for near focusing are produced by an increase in the optical power of the crystalline lens, first identified by Thomas Young (1801). ³ Young was able to identify through a series of elegant experiments that the radius of curvature of both surfaces of the crystalline lens decreased during accommodation, and the theory of decreased tension was subsequently developed by Helmholtz (1865) to describe the physical changes in the ­crystalline lens during accommodation.⁴