Editing Reptile (section)

===Vision===
Most reptiles are [[Diurnality|diurnal]] animals. The vision is typically adapted to daylight conditions, with color vision and more advanced visual [[depth perception]] than in amphibians and most mammals.

Reptiles usually have excellent vision, allowing them to detect shapes and motions at long distances. They often have poor vision in low-light conditions. Birds, crocodiles and turtles have three types of [[Photoreceptor cell|photoreceptor]]: [[rod cell|rods]], single [[Cone cell|cones]] and double cones, which gives them sharp color vision and enables them to see [[ultraviolet]] wavelengths.<ref name=Brames>{{Cite journal |journal=Iguana: Conservation, Natural History, and Husbandry of Reptiles |last=Brames |first=Henry |title=Aspects of Light and Reptile Immunity |url=https://www.academia.edu/6822325 |publisher=International Reptile Conservation Foundation |volume=14 |issue=1 |year=2007 |pages=19–23}}</ref> The lepidosaurs appear to have lost the [[duplex retina]] and only have a single class of receptor that is cone-like or rod-like depending on whether the species is diurnal or nocturnal.<ref>{{cite journal | url=https://www.sciencedirect.com/science/article/abs/pii/S2352154619300257 | doi=10.1016/j.cobeha.2019.10.009 | title=The evolutionary ecology of bird and reptile photoreceptor spectral sensitivities | journal=Current Opinion in Behavioral Sciences | series=Visual perception | date=December 2019 | volume=30 | pages=223–227 | last1=Osorio | first1=Daniel }}</ref> In many burrowing species, such as [[blind snake]]s, vision is reduced.

Many [[Lepidosauria|lepidosaurs]] have a photosensory organ on the top of their heads called the [[parietal eye]], which are also called [[third eye]], [[pineal eye]] or [[pineal gland]]. This "eye" does not work the same way as a normal eye does as it has only a rudimentary retina and lens and thus, cannot form images. It is, however, sensitive to changes in light and dark and can detect movement.<ref name=Brames/>

Some snakes have extra sets of visual organs (in the loosest sense of the word) in the form of [[Loreal pit|pits]] sensitive to [[infrared]] radiation (heat). Such heat-sensitive pits are particularly well developed in the [[pit vipers]], but are also found in [[boidae|boas]] and [[pythonidae|pythons]]. These pits allow the snakes to sense the body heat of birds and mammals, enabling pit vipers to hunt rodents in the dark.{{efn|
"The copperhead is a pit viper and, like others pit vipers, it has heat-sensitive pit organs on each side of its head between the eye and the nostril. These pits detect objects that are warmer than the environment and enable copperheads to locate nocturnal, mammalian prey."<ref>{{cite web |title=Northern copperhead |date=25 April 2016 |website=Smithsonian's National Zoo & Conservation Biology Institute |url=https://nationalzoo.si.edu/animals/northern-copperhead |access-date=12 February 2020}}</ref>
}}

Most reptiles, as well as birds, possess a [[nictitating membrane]], a translucent third eyelid which is drawn over the eye from the inner corner. In crocodilians, it protects its eyeball surface while allowing a degree of vision underwater.<ref>{{cite encyclopedia |title=Nictitating membrane |series=Anatomy |encyclopedia=Encyclopædia Britannica |lang=en |url=https://www.britannica.com/science/nictitating-membrane |access-date=2020-02-20}}</ref> However, many squamates, geckos and snakes in particular, lack eyelids, which are replaced by a transparent scale. This is called the [[brille]], spectacle, or eyecap. The brille is usually not visible, except for when the snake molts, and it protects the eyes from dust and dirt.<ref>{{cite news |title=Catalina Island Conservancy |website=www.catalinaconservancy.org |url=https://www.catalinaconservancy.org/index.php?s=news&p=article_149 |access-date=2020-02-20}}</ref>