Eye accommodation is the process by which the vertebrate eye changes its optical power to maintain a clear image or focus on an object as its distance varies). It is the natural response of the vision system to examine something nearby. The following are key points about eye accommodation:

• Definition: Eye accommodation is the ability of the eye to change the focal length of the lens by changing the curvature of the eye lens.

• Process: Eye accommodation allows the eye to automatically adjust focus from seeing things at a distance and "tune" it to seeing nearer objects. The process is achieved primarily by the lens changing its shape when focusing shifts from distant to near objects and vice versa.

• Structures involved: The structures involved in eye accommodation include the cornea, lens, ciliary muscle, and zonular fibers.

• Theories of accommodation: Different theories have been proposed to describe the mechanism of accommodation, including the Helmholtz theory of accommodation and the Schacher theory of accommodation.

• Clinical significance: Eye accommodation typically weakens with age, forcing most people to get corrective lenses after age 40. Dysfunction of the accommodation reflex can be physiological, pathological, or pharmacological.

In summary, eye accommodation is a natural process that allows the eye to adjust its focus to maintain a clear image or focus on an object as its distance varies. It involves changes in the curvature of the eye lens and is achieved through the coordinated action of several structures in the eye.