Which Animal Has The Largest Number of Eyes?

Spiders might seem like good contenders for the title of ‘most eyes in the animal kingdom’, but even with an impressive eight, they don’t come close to the record holders. If you’re looking for animals with lots of eyes, the best place to search is under the sea.

Nautiluses and giant clams have eyes like pinhole cameras; rather than having a lens, they simply have a hole. This hole functions a little like a pupil, allowing the animals to vary how much light enters the eye. These primitive eyes are not great for building up detailed pictures of the environment, but they can rapidly detect changes in light and shadow, perfect for detecting movement nearby.

Giant clams need this ability because they have colonies of photosynthesising algae living in their bodies. The clams open up to expose this algae to the light, allowing it to grow, but if something dangerous swims overhead, they need to snap shut for protection. To do this, they have not one or two, but thousands of tiny eyes lining each side of their mantle.