Why can’t we see colours in dim light?

Colour vision depends on cone cells, which need bright light to work. In dim light only the more sensitive rod cells respond, and they cannot distinguish colours.

What are the three types of cone cells?

There are three types of cones sensitive to red, green and blue light. Their combined stimulation lets us perceive the full range of colours.

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Difference Between Rod Cells and Cone Cells

The retina has two kinds of photoreceptor cells - rods and cones - that respond to light differently.

In short

Rod cells enable vision in dim light and detect only shades of grey (black-and-white); cone cells enable vision in bright light and detect colour.

Rod Cells vs Cone Cells - Comparison Table

Basis	Rod Cells	Cone Cells
Pigment	Rhodopsin (visual purple)	Photopsin (iodopsin)
Vision type	Dim-light / night (scotopic)	Bright-light / day (photopic)
Colour vision	No (black & white)	Yes (colour)
Sensitivity to light	High	Low
Location	Mainly peripheral retina	Concentrated at fovea
Number	More numerous (~120 million)	Fewer (~6–7 million)

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Frequently Asked Questions - Rod Cells vs Cone Cells

Why can’t we see colours in dim light?: Colour vision depends on cone cells, which need bright light to work. In dim light only the more sensitive rod cells respond, and they cannot distinguish colours.
What are the three types of cone cells?: There are three types of cones sensitive to red, green and blue light. Their combined stimulation lets us perceive the full range of colours.

Difference Between Rod Cells and Cone Cells

Rod Cells vs Cone Cells - Comparison Table

Frequently Asked Questions - Rod Cells vs Cone Cells

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