Spiders are popularly known for having many eyes (although this varies greatly among the different species, with some having two, four, six or eight eyes). The Ogre-faced spider has six eyes, but it looks as if it only had two because the middle pair is greatly enlarged. This is an adaptation for a nocturnal lifestyle; ogre faced spiders have superb night vision not only because of their huge eyes, but because of an extremely light sensitive layer of cells covering them.
This membrane is so sensitive in fact, that it is destroyed at dawn and a new one is produced every night. Ogre faced spiders are unusual because they can see perfectly at night even though they lack tapetum lucidum, a reflective membrane that helps others spiders (and other predators such as cats) to see in low light conditions. As a matter of facts, scientists believe that ogre faced spiders have better night vision than cats, sharks, or even owls (which can see up to 100 times better than humans at night!).
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