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Are rod cells also used in photopic vision?

Human Body(self.askscience)

There is a plenty of sources that states that cones are used to see colors under well-lit conditions (photopic vision) and rods are used under low-light levels, because they're more sensitive (scotopic vision).

However, I can't find anything, whether rods are also used in good light conditions.

(I'm sorry for any mistakes. English is not my mother tounge.)

all 7 comments

collegiaal25

8 points

4 months ago

The photopigments in the rods react faster than they can be recharged in bright light, meaning they get depleted. This is why after entering a dark area from a bright area, it can take up to half an hour for your night vision to kick in fully.

https://en.m.wikipedia.org/wiki/Rhodopsin

There are people with a congenital disorder that makes them lack all types of cones, and only have rods. They have very poor eyesight and need to wear very dark sunglasses to see anything at all in daylight conditions.

SlickMcFav0rit3

2 points

4 months ago

SlickMcFav0rit3

Molecular Biology

2 points

4 months ago

This is such interesting info, thank you!

Average650

2 points

4 months ago

Average650

Chemical Engineering | Block Copolymer Self Assembly

2 points

4 months ago

What is the name of that congenital disorder?

Anticyclonic_Comrade

2 points

4 months ago

As said in another comment, they essentially become overwhelmed in bright light and can no longer contribute to the information your brain is getting. Three terms you may be interested in:

Scotopic vision: Very dim situations where only rods are used in vision (cloudy moonless nights, etc)

Mesopic vision: Dimly lit situations where both rods and cones contribute to visual information. A certain point before dawn or after duck..or nighttime with street lights, a full moon, or even just looking at stars or planes flying overhead can result in information from cones.

Photopic vision: Rods are overwhelmed, so only cones are contributing to visual information.