Editing Photoreceptor cell (section)

== Difference between rods and cones ==
{{main|Cone cell|Rod cell}}

Comparison of human rod and cone cells, from [[Eric Kandel]] et al. in ''[[Principles of Neural Science]]''.<ref name="Kandel">{{cite book |last= Kandel |first= E. R. |author2= Schwartz, J.H. |author3= Jessell, T.M. |title= Principles of Neural Science |edition= 4th |year= 2000 |publisher= McGraw-Hill |location= New York |isbn= 0-8385-7701-6 |pages= [https://archive.org/details/isbn_9780838577011/page/507 507–513] |url= https://archive.org/details/isbn_9780838577011/page/507 }}</ref>
{| class="wikitable"
|-
!Rods
!Cones
|-
|Used for [[scotopic vision]] (vision under low light conditions)
|Used for [[photopic vision]] (vision under high light conditions)
|-
|Very light [[Stimulus (physiology)|sensitive]]; sensitive to scattered light
|Not very light sensitive; sensitive only to direct light
|-
|Loss causes [[night blindness]]
|Loss causes [[legal blindness]]
|-
|Low visual acuity
|High visual acuity; better spatial resolution
|-
|Not present in [[Fovea centralis|fovea]]
|Concentrated in [[Fovea centralis|fovea]]
|-
|Slow response to light, stimuli added over time
|Fast response to light, can perceive more rapid changes in stimuli
|-
|Have more pigment than cones, so can detect lower light levels
|Have less pigment than rods, require more light to detect images
|-
|Stacks of membrane-enclosed disks are unattached to cell membrane directly
|Disks are attached to outer membrane
|-
|About 120 million rods distributed around the retina<ref name =Schacter137/>
|About 6 million cones distributed in each retina<ref name =Schacter137/>
|-
|One type of [[photosensitive]] pigment
|Three types of [[photosensitive]] pigment in humans
|-
|Confer achromatic vision
|Confer color vision
|}