How the eye works – Higher

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, this allows the light rays to refract (bend) more strongly.

To focus on a distant object – the lens is pulled thin, this allows the light rays to refract slightly.

PositionCiliary musclesSuspensory ligamentsMuscle tensionLens shapeRefraction
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