IFL Science tells us that "xanthism" is a kind of albinism found in some animals that produces a skin that is yellow or orange. Last year, sport fishermen near the Tortuguero National Park in Costa Rica hooked a nurse shark (Ginglymostoma cirratum) that measured about six and a half feet long. It has pure white eyes with no discernible irises.
Scientists who published an article about the fish note that it is the first case of xanthism found in this species, as well as any species in the Caribbean Sea. The shark was probably healthy and its unique condition did not prevent it from feeding successfully.
-via Massimo