Final answer:
Accommodation is the process by which the eye adjusts its lens shape and focal length to focus light on the retina for clear vision at different distances. It involves the ciliary muscles and is crucial for clear vision both near and far. Corrective lenses help in cases of myopia and hyperopia to bring the image into focus on the retina.
Step-by-step explanation:
Accommodation refers to the eye's ability to adjust its focal length to produce a clear image on the retina, regardless of whether the observed object is near or far. The lens of the eye changes shape to achieve this adjustment, a process that is essential for maintaining clear vision at different distances. This ability of the eye is crucial for activities such as reading, which require the eye to focus on close objects, and for looking at distant objects where the lens has reduced power and is relaxed.
For clear vision to be achieved, the image produced by the lens must fall precisely on the retina. The ciliary muscles control the curvature of the eye lens, making it thicker for nearby objects and thinner for distant ones. In conditions like near sightedness (myopia) and farsightedness (hyperopia), corrective lenses are used to adjust the focal point so that the image falls on the retina, allowing for clear vision.