All dragonfly species have excellent vision. Each compound eye is comprised of several thousand elements known as facets or ommatidia. These ommatidia contain light-sensitive opsin proteins, thereby functioning as the visual sensing element in the compound eye. But unlike humans, day-flying dragonfly species have four or five different opsins, allowing them to see colors that are beyond human visual capabilities, such as ultraviolet (UV) light. Together, these thousands of ommatidia produce a mosaic of “pictures” but how this visual mosaic is integrated in the insect brain is still not known.

@GrrlScientist