How do its compound eyes work?
The human eye works like a camera, in that it uses a large light refractive lens to focus light onto a large photosensitive retina at the back of the eyeball. In contrast, the eyes of mantis shrimps and many other Crustaceans are classified as “apposition compound eyes”, very different from the “simple camera eyes” of humans. Apposition compound eyes are composed of many tiny optical elements (ommatidia), each with its own cornea and crystalline cone. Light rays must be aimed directly into an individual element to be sensed by the underlying visual pigments; the responses of the thousands of these elements are integrated to form an image. In the other major type of eye found in Arthropods, “superposition compound eyes”, a cluster of nearby optical elements direct their light rays onto the same patch of visual pigment. Superposition eyes perform better at low light levels, but the apposition eyes of mantis shrimps have better resolution than many types of superposition eyes. A truly rem
