Sclera nitrogenous sugar, hexosamine) to embed the fibrils. The cornea, unlike the sclera, has five layers. The middle, thickest layer is also called the stroma. The sclera, like the cornea, contains a basal endothelium, above which there is the lamina fusca, containing a high count of pigment cells. Sometimes, very small gray-blue spots can appear on the sclera, a harmless condition called scleral melanocytosis. Human eyes are somewhat distinctive in the animal kingdom in that the sclera is very plainly visible whenever the eye is open. This is not just due to the white colour of the human sclera, which many
Eye bank diseases such as HIV, hepatitis B, hepatitis C, human cytomegalovirus, syphilis, and sometimes others. The blood type is also tested, although corneas do not receive any blood supply and match typing is not necessary for transplantation. If the entire eye is enucleated during the original recovery, then the cornea and part of the sclera are removed and placed in a container with preservation medium, and the sclera is cleaned and then preserved in alcohol. The corneas are visually examined and evaluated underneath a slit-lamp, and the number of endothelial cells are counted underneath a specular microscope. The Eye Bank Association