Appaloosa occurs in several overlay patterns on one of several recognized base coat colors. There are three other distinctive, "core" characteristics: mottled skin, striped hooves, and eyes with a white sclera. Skin mottling is usually seen around the muzzle, eyes, anus, and genitalia. Striped hooves are a common trait, quite noticeable on Appaloosas, but not unique to the breed. The sclera is the part of the eye surrounding the iris; although all horses show white around the eye if the eye is rolled back, to have a readily visible white sclera with the eye in a normal position is a distinctive
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