SIGHT

The accomodation - near vision.
The visual accommodation enables to send a clear image to the retina, either in far or near vision.
It is done by deformation of the eye lens, elastic lens. The ciliary muscles (Muller-Rouget muscle, in yellow, and Brucke muscle, in red) contract or relax, generating or not a traction of the zonula (or zonule of Zinn, the suspensory ligament of the lens). The eye lens is then flattened or bulged.
To switch in near vision, the Muller-Rouget muscle contracts whereas the Brucke muscle relaxes, causing the tension of the zonula. The eye lens bulges because of its elasticity.

See. images 0351707 for the disaccommodation, 0351607 for the anatomy.