Editing Peripheral vision (section)

==Extreme peripheral vision==
[[File:Mairead cropped.png|thumb|Side-view of the human eye, viewed approximately 90° temporal, illustrating how the iris and pupil appear rotated towards the viewer due to the optical properties of the cornea and the aqueous humor.]]
When viewed at large angles, the iris and pupil appear to be rotated toward the viewer due to the optical refraction in the cornea. As a result, the pupil may still be visible at angles greater than 90°.<ref name="SpringStiles1948">{{cite journal|last1=Spring|first1=K. H.|last2=Stiles|first2=W. S.|title=Apparent Shape and Size of the Pupil Viewed Obliquely|journal=British Journal of Ophthalmology|volume=32|issue=6|year=1948|pages=347–354|issn=0007-1161|doi=10.1136/bjo.32.6.347|pmc=510837|pmid=18170457}}</ref><ref name="FedtkeManns2010">{{cite journal|last1=Fedtke|first1=Cathleen|last2=Manns|first2=Fabrice|last3=Ho|first3=Arthur|title=The entrance pupil of the human eye: a three-dimensional model as a function of viewing angle|journal=Optics Express|volume=18|issue=21|year=2010|pages=22364–76|issn=1094-4087|doi=10.1364/OE.18.022364|pmc=3408927|pmid=20941137|bibcode=2010OExpr..1822364F }}</ref><ref name="MathurGehrmann2013">{{cite journal|last1=Mathur|first1=A.|last2=Gehrmann|first2=J.|last3=Atchison|first3=D. A.|title=Pupil shape as viewed along the horizontal visual field|journal=Journal of Vision|volume=13|issue=6|year=2013|pages=3|issn=1534-7362|doi=10.1167/13.6.3|pmid=23648308|url=http://www.journalofvision.org/content/13/6/3.full|doi-access=free}}</ref>

===Cone-rich rim of the retina===
The rim of the retina contains a large concentration of cone cells. The retina extends farthest in the superior-nasal 45° quadrant (in the direction from the pupil to the bridge of the nose) with the greatest extent of the visual field in the opposite direction, the inferior temporal 45° quadrant (from the pupil of either eye towards the bottom of the nearest ear). Vision at this extreme part of the visual field is thought to be possibly concerned with threat detection, measuring optical flow, color constancy, or circadian rhythm.<ref name="MollonRegan1998">{{cite journal|last1=Mollon|first1=J D|last2=Regan|first2=B C|last3=Bowmaker|first3=J K|title=What is the function of the cone-rich rim of the retina?|journal=Eye|volume=12|issue=3b|year=1998|pages=548–552|issn=0950-222X|doi=10.1038/eye.1998.144|pmid=9775216|url=http://vision.psychol.cam.ac.uk/jdmollon/papers/MollonReganBowmaker.pdf|doi-access=free}}</ref><ref name="Williams1991">{{cite journal|last1=Williams|first1=Robert W.|title=The human retina has a cone-enriched rim|journal=Visual Neuroscience|volume=6|issue=4|year=1991|pages=403–6|issn=0952-5238|doi=10.1017/S0952523800006647|pmid=1829378|s2cid=10369867 }}</ref><ref name="ToRegan2011">{{cite journal|last1=To|first1=M.P.S.|last2=Regan|first2=B.C.|last3=Wood|first3=Dora|last4=Mollon|first4=J.D.|title=Vision out of the corner of the eye|journal=Vision Research|volume=51|issue=1|year=2011|pages=203–214|issn=0042-6989|doi=10.1016/j.visres.2010.11.008|pmid=21093472|doi-access=free}}</ref>