Re: How is the cornea of the eye transparent?

The alternating layers of the collagen fibrils are also layers where the fibres are parallel in each layer

These fibres are large enough to scatter visible light and they do. However, they scatter in opposing and overall correcting fashion as the direction in each layer is alternating with the one above or below. the net light scatter through the tissue is then zero apparently from one side to the next.

Ken Mitton

Moderator's note:
The cornea is also avascaular, lacking blood vessels which would affect transparency. Normal hydration of the cornea is also important in maintaing its transparency, and appropriate distance among the collagen fibrils.