Big Eyes

December 19, 2009
By Damond Benningfield

One of the most colorful creatures in the oceans can see colors better than just about any other animal. In fact, the mantis shrimp may have the most complicated eyes of any creature on Earth.

The mantis shrimp may have the most complicated eyes of any creature on Earth. Credit: Wikipedia

Many organisms have developed unusual eyes to help them see in the dark marine environment. Many of them can see wavelengths of light that are invisible to human eyes, for example. And they can detect the direction in which light waves move -- a handy tool for enhancing contrast and detecting subtle motion.

The colossal squid senses its way through the dark with eyes bigger than a basketball -- bigger than those of any other creature. And its brain is devoted mainly to processing visual signals.

In terms of visual complexity, though, you can’t beat the mantis shrimp, a small crustacean that looks like a cross between a shrimp and a praying mantis. While some species are a bit drab, others look like they’re getting ready for a Technicolor screen test -- they’re decked out in brilliant shades of red, blue, and green.

Their compound eyes allow them to see up to 12 bands of color, compared to just three for human eyes. What’s more, they see light’s polarization -- the way the light waves travel. It’s what we see when we put on a pair of polarized sunglasses -- a technique that enhances contrast and sharpens the view. Mantis shrimp even see a rare type of polarization that few other organisms can see.

These sharp eyes may help the mantis shrimp pick out mates, or see nearly transparent prey -- all in the blink of an eye.