Which structure is responsible for accommodation?

The crystalline lens is the structure responsible for accommodation, which is the process by which the eye adjusts its optical power to focus on objects at various distances. This is achieved through the actions of the ciliary muscles that control the shape of the lens. When these muscles contract, the lens becomes more rounded, increasing its optical power and allowing the eye to focus on nearby objects. Conversely, when the ciliary muscles relax, the lens flattens to focus on distant objects.

Understanding the role of the crystalline lens in accommodation is critical for various aspects of visual health and is particularly relevant in discussions surrounding presbyopia, a condition where the lens loses its ability to change shape effectively with age. Other structures like the tear film, fornix, and tarsal plate serve different functions within the eye, such as lubrication and eyelid support, but they do not directly participate in the accommodation process.