Preliminary Characterization of Human Crystalline Lens Geometry as a Function of Accommodation and Age

Accommodation is a dynamic visual process involving the controlled deformation of the crystalline lens by the ciliary muscle. In the unaccommodated state (focus on infinity), the lens is stretched to its thinnest along the visual axis, and its curvature is at its flattest. The accommodative process, which increases the refractive contribution of the lens to the overall system, occurs through a controlled elastic recovery by the lens, resulting in increased axial lens thickness and sharpness of curvature. With increasing age, the closest focus obtainable through this process recedes, resulting eventually in the condition termed presbyopia.