"The rods are more numerous of the photoreceptors, some 120 million, and are the more sensitive than the cones. However, they are not sensitive to color. [snippage] These rods are responsible for night vision, our most sensitive motion detection, and our peripheral vision. "
There's probably more to it. Someone will be along shortly to clarify.
It is pretty much true. There are two types of receptors in the eye: rods and cones. Rods are more sensitive to light and motion which allows them to pick up light in low-light settings. However, they do not pick up color at all. Cones are able to pick up color and detail, but they are less sensitive to light. That's why you don't see colors as well in dimly lit areas. The outside edges of the retina contain only rods, so your vision is more or less colorblind in that area. As you move towards the middle of the retina, there are more and more cones added to the mix. Eventually, you get to the fovea, an area near the center of the retina that consists only of cones. This area of the eye picks up the most detail, and when you focus your attention on something, that's the part of retina you're using. You probably do perceive colors in your peripheral vision, but that is the brain filling in the colors for you. They eye itself is only sensing things in monochrome in your peripheral vision.
-------------------- Disclaimer: I might know something about everything, but I don't know much about anything. Posts: 293 | From: Nashville, TN | Registered: Dec 2003
| IP: Logged |