The mantis shrimp’s eyes sit on stalks and are able to move independently of each other, this gives them seamlessly 360 degree vision. Another important aspect of the mantis shrimp’s vision is that each eye has what is called “trinocular vision”. That means that each eye can individually gauge depth and distance of an object with three separate regions. While we only see three different colours the mantis shrimp is known to see twelve different. They are able to see twelve different colours because they have twelve photoreceptors.
As stated before the mantis shrimp’s vision can be attributed to the incredible amount of photoreceptors that they possess (they have 12!). Each photoreceptor is contains seven cells call “rhabdoms” all of which are arranged in a cylinder. Each of the rhabdoms are comprised of thousands of “microvilli” All microvilli are arranged to face one direction creating gap that only vibrating light can enter through. Three out of the seven rhabdoms are sensitive to one plane of polarised light and the other four are sensitive to the plane that is perpendicular to the plane of light received by the first three.
Another interesting fact about the mantis shrimps vision is that they are the only known living animal to have the ability to see ‘circularly polarised light’ which allows them to the see the world in a much higher contrast. This unique ability is enabled by mantis shrimp’s 8th rhabdom in each photoreceptor. The eighth rhabdom sits on top and its slit is angled at 45 degrees to the seven below it. It’s this cell that converts circularly polarised light into its linear version.