Editing Pretectal area (section)

===Pupillary light reflex===
{{Main|Pupillary light reflex}}
[[File:Eye dilate.gif|right|thumb|Pupillary constriction resulting from the pupillary light reflex is mediated by the olivary and posterior pretectal nuclei.]]
The pupillary light reflex is mediated by the pretectum.<ref name="Magoun" /> This reflex is responsible for the constriction of the pupils upon light's entering the eye<!--or "upon the entering of light into the eye" but not as written before-->. Several pretectal nuclei, in particular the ON, receive illuminance information from the ipsilateral side of the retinas of both eyes via the optic tract. Nuclei in the ON are known to gradually increase in activation in response to increasing levels of illuminance. This information is then relayed directly to the Edinger-Westphal nucleus, which proceeds to relay the command to constrict the pupils to the pupillary sphincter via the ciliary ganglion.<ref name="clinical neuroanatomy" /><ref>{{cite journal | vauthors = Gamlin PD, Zhang H, Clarke RJ | title = Luminance neurons in the pretectal olivary nucleus mediate the pupillary light reflex in the rhesus monkey | journal = Experimental Brain Research | volume = 106 | issue = 1 | pages = 169–76 | year = 1995 | pmid = 8542972 | doi = 10.1007/bf00241367 | s2cid = 24936336 }}</ref>