#851 Lens

The lens in the human eye works much like the lens in a camera. Just as a camera [1] its focus, the lens changes its shape to bend and focus the light a second time, ensuring that you have a clear and [2] image of whatever you are looking at. Whether the object is close or [3] away, the lens adapts accordingly. Structurally, the lens is made up of water and protein, which together allow it to remain transparent and flexible throughout much of life.