Nah- und Fernakkomodation/en

In German, accommodation means adaptation. Focusing is always done by changing the shape of the lens, which then changes its refractive power. Nahakkomodation increases the refractive power of the lens. This causes the so-called ciliary muscle, which surrounds the lens circularly, to contract, relaxing the zonula fibres and giving the lens a more rounded shape due to its inherent elasticity. If the ciliary muscle slackens, the zonula fibres are stretched and the lens becomes flatter. Their refractive power decreases to its lowest value and our eyes are adjusted for distant accomodation: In this way distant objects can be seen clearly.