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,
Eye of the Stalker well as a video of Beth. When Stephen attempts to break into her home one night, Liz sets out to locate Beth after recognizing her from the video. They both join forces to catch Stephen in the act, using Beth as bait. Liz gives Beth a loaded gun, which the latter eventually uses when she sees Stephen holding Martha and threatening to slit her throat with a knife. Beth fires a warning shot to deter Stephen, and he is finally arrested. Eye of the Stalker Eye of the Stalker (a.k.a. Moment of Truth: Eye of the Stalker and Eye of