Editing Cone cell (section)

===Distribution===
[[File:ConeMosaics.jpg|thumb|250px|Illustration of the distribution of cone cells in the fovea of an individual with normal color vision (left), and a color blind (protanopic) retina. Note that the center of the fovea holds very few blue-sensitive cones.]]
[[File:Human photoreceptor distribution.svg|thumb|250px|Distribution of rods and cones along a line passing through the fovea and the blind spot of a human eye<ref>[https://foundationsofvision.stanford.edu/chapter-3-the-photoreceptor-mosaic Foundations of Vision], Brian A. Wandell</ref>]]
While rods outnumber cones in most parts of the retina, the [[Fovea centralis|fovea]], responsible for sharp central vision, consists almost entirely of cones. The distribution of photoreceptors in the retina is called the [[retinal mosaic]], which can be determined using [[photobleaching]]. This is done by exposing dark-adapted retina to a certain wavelength of light that paralyzes the particular type of cone sensitive to that wavelength for up to thirty minutes from being able to dark-adapt, making it appear white in contrast to the grey dark-adapted cones when a picture of the retina is taken. The results illustrate that '''S''' cones are randomly placed and appear much less frequently than the '''M''' and '''L''' cones. The ratio of '''M''' and '''L''' cones varies greatly among different people with regular vision (e.g. values of 75.8% '''L''' with 20.0% '''M''' versus 50.6% '''L''' with 44.2% '''M''' in two male subjects).<ref>{{cite journal | author = Roorda A. | author2 = Williams D.R. | year = 1999 | title = The arrangement of the three cone classes in the living human eye | journal = Nature | volume = 397 | issue = 6719| pages = 520–522 | pmid=10028967 | doi = 10.1038/17383 | bibcode = 1999Natur.397..520R | s2cid = 4432043 }}</ref>