Accommodation Length

Accommodation is the process of adapting the eye to changing image distances or changing light levels. As a result of this process, a change in the shape and size of the refractive elements in the lens of the eye occurs: an increase in the curvature of the lens or its relaxation due to the contraction of smooth muscle cells. Thus, the length of the anteroposterior axis of the eye decreases from its length during embryogenesis. In physiology, up to 25 years of age, the growth of the eyeball increases at a constant rate of 4 mm per year. The limit of accommodative ability ends at approximately the age of 30 years, then it begins to decrease. Most people over the age of 40 are unable to focus their eyes at close range for long periods of time. Only about 5% retain this ability. The ability to change pupil size is an innate ability of the body and is not related to age. However, with age, the elasticity of the lens decreases, which can lead to shortened accommodation or even to the fact that the eyeballs are unable to change the depth of focus.