Sclera However, acid burns, even severe ones, seldom result in loss of the eye. Alkali burns, on the other hand, such as those resulting from exposure to ammonium hydroxide or ammonium chloride or other chemicals with a pH above 11.5, will cause cellular tissue in the sclera to saponify and should be considered medical emergencies requiring immediate treatment. Yellowing of the sclera is a visual symptom of jaundice. In very rare but severe cases of kidney failure and liver failure, the sclera may turn black. Sclera The sclera, also known as the white of the eye, is the opaque, fibrous, protective,
Cooperative eye hypothesis sclera, and irises. Human eyes are also larger in proportion to body size, and are longer horizontally. Among primates, humans are the only ones where the outline of the eye and the position of the iris can be clearly seen. The cooperative eye hypothesis was first proposed by H. Kobayashi and S. Khoshima in 2002 and was subsequently tested by Michael Tomasello and others at the Max Planck Institute for Evolutionary Anthropology in Germany. Researchers examined the effect of head and eye movement on changing gaze direction in humans and great apes. A human experimenter, observed by either a human