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Dragonfly with compound eyes. Author: David L. Green

A compound eye is a visual organ found in certain arthropods. The compound eye consists of between 12 and 1,000 ommatidia, little dark/bright sensors. The image perceived by the arthropod is "recalculated" from the numerous ommatidia which point in slightly different directions. In contrast to other eye types, there is no central lens or retina. Though the resulting image is poor in resolution, it can detect quick movements and, in some cases, the polarization of light. Dragonflies have about 30,000 facets to their compound eyes, giving them nearly a 360° field of vision. Photo credit: David L. Green

m:Image:Dragonfly eye 3811.jpg