To what kind of light are the rod light-sensitive receptors in the retina sensitive to?

Gnomon

Low level light of any colour. Jun 25 06, 2:50 PM

darkpresence

Low level light yes, but rods are not sensitive to colour. They "switch on" in the dark, rather slowly too which is why it takes your eyes a few minutes to adjust to darkness. Rods are also responsible for peripheral vision, which is why it's easier to see objects in the dark if you look to the side of them. Despite not registering colour, rods are much more numerous and sensitive than cones. http://hyperphysics.phy-astr.gsu.edu/hbase/vision/rodcone.html Jun 25 06, 4:55 PM

gmackematix

Which is why it is difficult to make out colours in very dim light. Jun 25 06, 8:33 PM

Gnomon

There is no such thing as "black and white light". As I said before, rods are sensitive to light of all colours, which means that they cannot be used to distinguish between colours, so all colours appear the same. Jun 26 06, 1:41 AM

darkpresence

The retina contains two types of photoreceptors, rods and cones. The rods are more numerous, some 120 million, and are more sensitive than the cones. However, they are not sensitive to color. The 6 to 7 million cones provide the eye's color sensitivity and they are much more concentrated in the central yellow spot known as the macula. In the center of that region is the " fovea centralis ", a 0.3 mm diameter rod-free area with very thin, densely packed cones. from the above link. Colour only exists by registration on the retina, it has no intrinsic quality of itself. If it doesn't register, it doesn't exist as such. Jun 26 06, 4:35 PM