Rods and Cones

The rod system functions best

in dim light, poorly, or not at all in bright light.

The cone system functions best

in bright light, poorly or not at all in dim light.

Rod system’s detail vision

is poor

Cone system’s detail vision

is good

Rod system relationship with colors

does not distinguish colors

Cone system relationship with colors

Subset distinguishes among colors

Rod system location

Mostly in periphery of retina

Cone system location

Mostly in fovea (center) of the retinaand surrounding area

Cone system receptive field

Small, with one or a few cones converging on a single ganglion cell; contributes to detail vision

Rod system receptive field

Large, due to convergence on ganglion cells; contributes to light sensitivity

Rods and cones are distributed

unevenly in the retina

Fovea

center of retina, high density of photoreceptors

Peripheral

sides of retina, low density of photoreceptors

Fovea has a ___ number of cones, and a ___ number of rods

high, low

Peripheral has a ___ number of cones, and a ___ number of rods

low, high

Fovea has the highest density of

L-cones and M-cones

Peripheral has the highest concentration of

S cones

Fovea’s impact on visual acuity

Greatest visual acuity/resolution

Peripheral impact on visual acuity

poor visual acuity

How many cones are within the eye

approximately 7 million

How many rods are within the eyes

approximately 120 million

How many types of rods are there

1

How many types of cones are there

3

Rods visual perception

sees in shades of gray

Cones visual perception

responsible for color perception

Rods are responsible for

night vision, light detection, and grayscale vision

Cones are responsible for

high visual acuity, color vision, and daytime vision