Stare-in-the-crowd effect evolved from a necessity for fast and accurate gaze perception for complex social interactions (Emery 2000). According to this model, an eye direction detector (EDD) mechanism - a neurocognitive system responsible for the rapid detection of eyes in the environment and their gaze direction – arose as a function of the geometry created by a dark circular iris relative to the white sclera (Baron-Cohen 1994). Specifically, it is contended that the increased ratio of exposed sclera in the eye outline of humans serves to enhance the velocity and acuity of gaze direction perception (Kobayashi and Kohshima 2001). Baron-Cohen, S. (1994)
Tache noir de la sclerotique eye, which becomes brown and then black within a few hours, upon which dust settles and the surface becomes wrinkled. Tache noir de la sclerotique Tache noire de la sclerotique (French for "Black spot of the sclera") is one of the ocular signs of death in which a reddish-brown discoloration is transversely arranged across the sclera. It occurs when the eyes are not completely closed so that the sclera is exposed to air. If the eyelids are open for a few hours after death, a film of cell debris and mucus forms two yellow triangles on the sclera, each at