What is amplitude of accomodation?

Amplitude of accommodation refers to the degree of adjustment the eye can make in order to focus on objects at varying distances. It is a measure of the range of changing optical power that the eye can achieve through the contraction and relaxation of the ciliary muscle and the adjustment of the curvature of the lens.

The amplitude of accommodation decreases with age, just like other functions of the eye. A normal amplitude of accommodation for a young adult is typically between 15 and 25 diopters (D), with a gradual decline in amplitude beginning around age 40. By age 60, the typical amplitude of accommodation is approximately 1-2 D.

The amplitude of accommodation can be affected by various factors including fatigue, stress, medications, and certain medical conditions. Additionally, people who have had refractive surgery may have a reduced amplitude of accommodation due to the changes in the shape of their cornea.

The amplitude of accommodation is an important measurement used in optometry and ophthalmology to evaluate the focusing ability of the eye, and to determine the need for corrective lenses such as glasses or contact lenses.