Scientists are trying to look through the eyes of a shark so they can understand why some can glow.

There are two species of catsharks that use biofluorescence — the chain catshark and the swell shark. But no one can say for certain why these sharks sometimes give off a green light.

So researchers with the American Museum of Natural History developed a camera that essentially mimics the way a shark eye sees.

Catsharks live deep underwater, where there is mostly only blue light. Researchers found that the sharks can only see in the blue and green spectra.

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Under the natural, low light, the sharks blend in with their surroundings. But through the lens of the shark-eye camera, they glowed a bright green, making them really stand out in their environment.

Which leads scientists to believe the catsharks' glow may help potential mates find each other.

However, right now that's just a guess, and experts say they need to know more before they can determine exactly why catsharks and other fish glow.