How the eye works

Accommodation is the process of changing the shape of the lens to focus on near or distant objects.

To focus on a near object - the lens becomes thicker which allows the light rays to refract (bend) more strongly.

To focus on a distant object - the lens is pulled thin which allows the light rays to refract slightly.

Position of objectCiliary musclesSuspensory ligamentsMuscle tension on lensLens shapeRefraction of light rays
NearContractSlacken / loosenLowFat / thickerLight is refracted strongly
DistantRelaxStretched / tightenHighThinLight is only refracted slightly
Diagram showing how an image focuses at the retinaThe lens changes shape to focus on near and distant objects