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 Eye in the Door The Eye in the Door The Eye in the Door is a novel by Pat Barker, first published in 1993, and forming the second part of the "Regeneration" trilogy. "The Eye in the Door" is set in London, beginning in mid-April, 1918, and continues the interwoven stories of Dr William Rivers, Billy Prior, and Siegfried Sassoon begun in "Regeneration". It ends some time before the conclusion of the First World War later the same year. The third part of the trilogy, "The Ghost Road", continues the story. Whereas "Regeneration" is an anomalous, but not unique, mixture of fact and fiction,