Editing Eye (section)

====Superposition eyes====
The second type is named the superposition eye. The superposition eye is divided into three types:
* refracting,
* reflecting and
* parabolic superposition

The refracting superposition eye has a gap between the lens and the rhabdom, and no side wall. Each lens takes light at an angle to its axis and reflects it to the same angle on the other side. The result is an image at half the radius of the eye, which is where the tips of the rhabdoms are. This type of compound eye, for which a minimal size exists below which effective superposition cannot occur,<ref name="Meyer-Rochow 2004">{{cite journal|last1=Meyer-Rochow|first1=VB|last2=Gal|first2=J|title=Dimensional limits for arthropod eyes with superposition optics|journal=Vision Research|date=2004|volume=44|issue=19|pages=2213–2223|doi=10.1016/j.visres.2004.04.009|pmid=15208008|doi-access=free}}</ref> is normally found in nocturnal insects, because it can create images up to 1000 times brighter than equivalent apposition eyes, though at the cost of reduced resolution.<ref>{{cite thesis|type=PhD |last=Greiner |first=Birgit |title=Adaptations for nocturnal vision in insect apposition eyes |publisher=Lund University |date=16 December 2005 |url=http://www4.lu.se/upload/GreinerThesis.pdf |access-date=13 November 2014 |url-status=dead |archive-url=https://web.archive.org/web/20130209164014/http://www4.lu.se/upload/GreinerThesis.pdf |archive-date=9 February 2013 }}</ref> In the parabolic superposition compound eye type, seen in arthropods such as [[mayfly|mayflies]], the parabolic surfaces of the inside of each facet focus light from a reflector to a sensor array. Long-bodied [[Decapoda|decapod crustaceans]] such as [[shrimp]], [[prawn]]s, [[crayfish]] and [[lobster]]s are alone in having reflecting superposition eyes, which also have a transparent gap but use corner [[mirror]]s instead of lenses.