Cockroaches See Through Mosaic Vision
Cockroaches are able to see multiple images at once through mosaic vision. This type of sight is a combination of multiple images produced by compound eyes. This type of vision has a higher sensitivity but lower resolution. This form of vision is most common at night.
Cockroaches have compound eyes which contain numerous tiny visual units (ommatidia). The eyes of cockroaches contain around 2000 ommatidia. These ommatidia are what help the cockroach see multiple images of an object. Cockroach mosaic vision is similar to human binocular vision but is characterized by higher sensitivity and lower resolution. Cockroaches can use mosaic vision to see objects very well even during darkness.
The different types of photoreceptors in the cockroach visual tract show varying locations and the spiking behavior of different types of responses. Using a microscope, we recorded the responses and estimated their location. We observed that these responses were spiking in the upper and lower two axons.
Cockroaches have mosaic vision and can discern specific colors. Because of their bichromatic eyes, they can see well in the green spectrum between 520 and 570 nm. They cannot perceive the red or orange wavelengths, but they are able to sense certain colors and are highly sensitive. Even during a moonless night, they can absorb up to one photon every ten seconds.