What do the rods and cones in the eye do?
There are two types of photoreceptors in the human retina, rods and cones. Rods are responsible for vision at low light levels (scotopic vision). They do not mediate color vision, and have a low spatial acuity. In the top figure, you can relate visual angle to the position on the retina in the eye.
Rod cells are photoreceptor cells in the retina of the eye that can function in less intense light than the other type of visual photoreceptor, cone cells. Rods are usually found concentrated at the outer edges of the retina and are used in peripheral vision.
- Although originally made of concrete, today's versions are more commonly brightly colored thermoplastic or rubber cones. Recycled PVCs from bottles can be used to create modern traffic cones. Not all traffic cones are conical. Pillar-shaped movable bollards fulfill a similar function.
- Medical Definition of Cone. Cone: A type of specialized light-sensitive cell (photoreceptor) in the retina of the eye that provides color vision and sharp central vision. By contrast, the rods are the retinal photoreceptors that provide side vision and the ability to see objects in dim light (night vision).
- The eye's outer layer is made of dense connective tissue, which protects the eyeball and maintains its shape. It is also known as the fibrous tunic. The fibrous tunic is composed of the sclera and the cornea.
Updated: 23rd September 2018