The lens focuses the light rays to allow you to see images. In the eye, the shape of the lens changes in order to focus the light so you can see both near and distant objects clearly. Normally the muscles of the eye can compress the lens enough so that objects as close as about 10 inches away can be seen clearly. The lens changes so that the light can be focused onto the retina in the back of the eye. The retina changes the light rays into nerve signals, which are sent to your brain through the optic nerve. These signals are interpreted by your brain and allow you to understand what you are seeing.