Editing Frog (section)

===Sight===
The eyes of most frogs are located on either side of the head near the top and project outwards as hemispherical bulges. They provide [[binocular vision]] over a field of 100° to the front and a total visual field of almost 360°.<ref name="Howard">{{cite book |last1=Howard |first1=Ian P. |url={{Google books|I8vqITdETe0C|page=651|plainurl=yes}} |title=Binocular Vision and Stereopsis |last2=Rogers |first2=Brian J. |publisher=Oxford University Press |year=1995 |isbn=978-0195084764 |page=651}}</ref> They may be the only part of an otherwise submerged frog to protrude from the water. Each eye has closable upper and lower lids and a [[nictitating membrane]] which provides further protection, especially when the frog is swimming.<ref name=Badger>{{cite book |title=Frogs |last=Badger |first=David |author2=Netherton, John |year=1995 |publisher=Airlife Publishing Ltd |isbn=978-1-85310-740-5 |pages=31–35 }}</ref> Members of the aquatic family [[Pipidae]] have the eyes located at the top of the head, a position better suited for detecting prey in the water above.<ref name=Howard/> The [[iris (anatomy)|iris]]es come in a range of colours and the pupils in a range of shapes. The [[common toad]] (''Bufo bufo'') has golden irises and horizontal slit-like pupils, the [[Agalychnis callidryas|red-eyed tree frog]] (''Agalychnis callidryas'') has vertical slit pupils, the [[poison dart frog]] has dark irises, the [[fire-bellied toad]] (''Bombina spp.'') has triangular pupils and the [[Dyscophus antongilii|tomato frog]] (''Dyscophus spp.'') has circular ones. The irises of the [[southern toad]] (''Anaxyrus terrestris'') are patterned so as to blend in with the surrounding camouflaged skin.<ref name=Badger/>

The distant vision of a frog is better than its near vision. Calling frogs will quickly become silent when they see an intruder or even a moving shadow but the closer an object is, the less well it is seen.<ref name=Badger/> When a frog shoots out its tongue to catch an insect it is reacting to a small moving object that it cannot see well and must line it up precisely beforehand because it shuts its eyes as the tongue is extended.<ref name=Exploratorium/> Although it was formerly debated,<ref>{{cite journal|title=Vision in frogs|last=Muntz|first=W. R. A.|author2=Scientific American Offprints|journal=Scientific American|publisher=W. H. Freeman|year=1964|volume=210|issue=3|pages=110–9|doi=10.1038/scientificamerican0364-110|pmid=14133069|bibcode=1964SciAm.210c.110M|asin=B0006RENBO|oclc=15304238}}</ref> more recent research has shown that frogs can see in colour, even in very low light.<ref>{{Cite journal|last1=Kelber|first1=Almut|last2=Yovanovich|first2=Carola|last3=Olsson|first3=Peter|date=April 5, 2017|title=Thresholds and noise limitations of colour vision in dim light|journal=Philosophical Transactions of the Royal Society B: Biological Sciences|language=en|volume=372|issue=1717|pages=20160065|doi=10.1098/rstb.2016.0065|issn=0962-8436|pmc=5312015|pmid=28193810}}</ref>
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