Scientists are discovering new structures and adaptations all the time. There are eyes with mirrors, eyes with optical fibres, and eyes with bifocal lenses. There are eyes that see in the dark, move around heads, or go into sleep mode. There are even eyes made of rock. This slideshow will take you on a tour of some of these recent eye-opening discoveries.
Pictured is a box jellyfish, which has 24 eyes of two different types. Link