Whale sharks protect their unlidded eyeballs with thousands of tiny teeth

Whale sharks have no eyelids to shield their vision from underwater debris, collisions, or parasites. Instead, marine biologists discovered that their eyes are protected by an extraordinary anatomical defense: thousands of tiny dermal denticles, or armored tooth-like scales, surrounding and covering the surface of each eyeball. In addition to this living eye armor, whale sharks can pull their entire eyeballs deep inside their head sockets, rotating them out of danger when approached by potential threats.

Sources

• Armored eyes of the whale shark and its functional significancejournals.plos.org ↗
• Whale sharkWikipedia ↗