So, what was a third eyelid doing in a human? Most refer to such bits of tissue as vestigial. The word means a structure that ...

Unlike the octopus's arms, which that animal often uses to move and carry ... the cuttlefish moves its lenses by reshaping its entire eye. Also, the cuttlefish's eyes are very large in proportion ...

Some are so well preserved that scientists have been able to use scanning electron microscope images to piece together their inner anatomy ... around eye for the most versatile animal of all.

Evidence for this function first came from studies of the organ's anatomy and its nerves as well ... this feature is unknown in any other extant animal. With the aid of the intracranial joint ...