Cooperative eye hypothesis Cooperative eye hypothesis The cooperative eye hypothesis is a proposed explanation for the appearance of the human eye. It suggests that the eye's distinctive visible characteristics evolved to make it easier for humans to follow another's gaze while communicating or while working together on tasks. Unlike other primates, human beings have eyes with a distinct colour contrast between the white sclera, the coloured iris, and the black pupil. This is due to a lack of pigment in the sclera. Other primates have pigmented sclerae that are brown or dark in colour. There is also a higher contrast between human skin,
The Mind's Eye & Mission of the Viyrans husband are causing problems to her domestic bliss. This story leads directly into the audio drama "The Bride of Peladon". The hallucinogenic plants in this story reappear in "Brotherhood of the Daleks". Mission of the Viyrans is a Big Finish Productions audio drama based on the long-running British science fiction television series "Doctor Who". It is a one-part story written by Nicholas Briggs and was released alongside a three-part story, "The Mind's Eye". The Doctor and Peri encounter the time travelling Viyrans on a holiday planet. "Mission of the Viyrans" completes the "Virus Strand" story arc, which also includes the