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,
Book of the Ten Treatises of the Eye the sclera, a thick, hard membrane which protects the inner parts of the nerves from injury. The chorioid, a thin and soft structure filled with veins and arteries, follows next and provides nourishment to the overall structure. Finally, the retina transmits nutrients to the lenses themselves. Hunayn then presents the system responsible for protecting the eye. From the outermost level, these are the conjunctiva, cornea, and uvea. While both the conjuctiva and cornea provide protection with minimizing hindrance to the lenses, the uvea has an extra function of concentrating the pneuma exiting out of the eye to prevent it from