aren't usually transparent. Where such biological materials share the same refractive index, light rays could reflect from deeper tissues and can pass across the boundary neatly, providing a level ...

When light passes through a material, the spatial arrangement of the material’s atoms can cause the light to undergo ...

This change in speed can cause the light to bend at the boundary between the two transparent materials. The change in direction of a beam of light as it travels from one material to another is ...