Scallop’s Unusual Visual System Composed Of 200 Eyes


Remarkably, this delicious seafood delicacy, the scallop, has 200 unusual eyes that function like a telescope, according to a new study. Its eyes are described as small poppy-seed-like black eyes that have lenses that focus light on one or two retinas.

The findings of the study were published in the journal Science on Dec.1. The study was led by scientists from Israel’s Weizmann Institute of Science and Lund University in Sweden, according to

The size of each of the scallop’s eyes is about a millimeter in diameter and has perfectly square and flat crystals, which develop into a mirrored mosaic. This reduces the surface defects that could allow the scallop to see a clear picture.

Its eyes lined along their outer edge are referred to as the mantle. There are also concave mirrors at the back of the scallop’s eyes. Each mirror is layered that makes the scallop have spatial vision.

The scientists used cryo-electron microscopy to view the details of the scallops. Benjamin Palmer, a co-author of the study and a biologist at the Weizmann Institute of Science in Rehovot, Israel, said that the guanine crystals that develop in the scallop’s eye mirror are perfectly square. He described it as really weird, adding that it is the first time they have seen a perfect square.


Palmer explained that guanine does not develop into crystal shapes. This means that the scallop is controlling the crystallization process. The team also discovered that the square crystals are arranged like bathroom tiles that form a smooth surface to reduce image distortion. Each of the scallop eyes is composed of 20 to 30 tiled sheets that create a reflective surface. It is just similar to a telescope that “pieces together hexagonal mirrors into one giant curve,” according to Science News.


The team also found that the scallop’s eye mirror has an unusual 3-D shape that could let the scallop focus light on one or two retinas. However, this depends on the angle of the incoming light. One retina is focused to dimmer light from the peripheral vision. Meanwhile, the other retina perceives the movement in bright light.

Experts are puzzled on how the scallop could make use of both retinas in the same eye. Another thing that perplexes scientists is why this sea creature has so many eyes. Finally, the intricacy of each eye also remains to be a mystery.