Editing Compound eye (section)

{{Short description|Visual organ found in arthropods such as insects and crustaceans}}
[[Image:Krilleyekils.jpg|thumb|Compound eye of [[Antarctic krill]] as imaged by an [[electron microscope]]]]

A '''compound eye''' is a [[Eye|visual organ]] found in [[arthropod]]s such as [[insect]]s and [[crustacean]]s. It may consist of thousands of [[ommatidium|ommatidia]],<ref>{{cite book |title=Insects and Spiders of the World. Volume 8: Scorpion fly - Stinkbug |chapter-url=https://archive.org/details/insectsspidersof0011unse/page/459 |chapter-url-access=registration |date=2003 |publisher=Marshall Cavendish |location=New York |isbn=978-0761473428 |page=[https://archive.org/details/insectsspidersof0011unse/page/459 459] |chapter=Senses. Insect eyes }}</ref> which are tiny independent photoreception units that consist of a [[cornea]], [[lens (anatomy)|lens]], and [[photoreceptor cell]]s which distinguish brightness and color. The image perceived by this [[arthropod eye]] is a combination of inputs from the numerous ommatidia, which are oriented to point in slightly different directions. Compared with single-aperture [[eye]]s, compound eyes have poor [[image resolution]]; however, they possess a very large view angle and the ability to detect fast movement and, in some cases, the [[Polarization (waves)|polarization]] of light.<ref>{{cite journal |last1=Völkel |first1=R. |last2=Eisner |first2=M. |last3=Weible |first3=K.J. |title=Miniaturized imaging systems |journal=Microelectronic Engineering |date=June 2003 |volume=67-68 |issue=8 |pages=461–472 |doi=10.1016/S0167-9317(03)00102-3|url=http://www.suss-microoptics.com/downloads/Publications/Miniaturized_Imaging_Systems.pdf|url-status=usurped |archive-url=https://web.archive.org/web/20081001225326/http://www.suss-microoptics.com/downloads/Publications/Miniaturized_Imaging_Systems.pdf |archive-date=2008-10-01 }}</ref> Because a compound eye is made up of a collection of ommatidia, each with its own lens, light will enter each ommatidium instead of using a single entrance point. The individual light receptors behind each lens are then turned on and off due to a series of changes in the light intensity during movement or when an object is moving, creating a flicker-effect known as the flicker frequency, which is the rate at which the ommatidia are turned on and off– this facilitates faster reaction to movement; [[honey bee]]s respond in 0.01s compared with 0.05s for humans.<ref>[https://books.google.com/books?id=kISACgAAQBAJ&dq=compound+eyes+elementary+motion+detectors+%28EMDs%29&pg=PA117 Biologically Inspired Computer Vision: Fundamentals and Applications]</ref>