Scallops, hardly the most complex of creatures, have intricate eyes that work like telescopes, say researchers. They hope this discovery can one day help us make our own telescopes more powerful.
For a paper published today in the journal Science, researchers used a few different microscope techniques to get a detailed view of how the king scallop, or Pecten maximus, is able to see. The scallop has 200 tiny eyes lining its mantle, or outside edge.
Each of these eyes contains tiny mirrors, which is different from how most animals, including humans, see. Our eyes use lenses (the cornea) that focus and bend the light passing through it. The light is focused into the retina, or the light-sensitive tissue layer at the back of the eye.
But scallop eyes, and powerful telescopes, use mirrors instead. Mirrors don't focus light but instead reflect it, which has a few advantages. Lenses can only deal with certain wavelengths of light, but mirrors can gather more types, and thus more information. Lenses are more likely to have engineering and design problems, which will make images unclear. And, at least for telescopes, it’s easier and cheaper to make a large mirror than a large lens, because lenses can be heavy and expensive.
We knew about the mirrors before, but we didn’t know just how they were put together. The scallop’s tiny mirrors are made from 20 to 30 layers of crystals, and the layers themselves are made of closely tiled crystal plates, like a mosaic. Each mirror is carefully calibrated to reflect the right wavelength. Together, it makes the picture clearer, and with its 200 eyes and a double-layered retina, scallop can see peripheral and central pictures at the same time.
The scallop is far from the only creature that has something to teach us about design. Lobster eyes, for example, can help us design better ways to see in low light. So don’t write off the scallop on your plate. Its eyes are mini versions of some of the most powerful telescopes.