How many rods and cones are found in a typical human retina?
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Photoreception
The mammalian eye has a cornea and a lens and functions as a dioptric system, in which light rays are refracted to focus on the retina.
A typical human retina contains approximately 130 million rods and about 7 million cones.1
These two types of photoreceptor cells serve distinct functions in human vision:
- Rods: These cells are highly sensitive to light and are responsible for perceiving size, shape, and brightness, particularly in low-light conditions. They do not perceive color or fine detail.12
- Cones: These cells are less sensitive to low illumination but are essential for color vision and the perception of fine detail. They are most densely concentrated in the fovea centralis, an area of the retina that contains no rods.12