Question

Why do you think that there are fewer color-sensitive photoreceptors along the periphery of our eyes? What kind of visual stimuli can we detect “out of the corner of our eyes”?

Answer 1

As we know our eyes have periphery vision, but it not clear. This is because periphery of retina has the highest concentration of rod photoreceptors and only a few cone photoreceptors. Our ability to detect color difference is largely restricted to peripheral level because the cellular basis of red-green color vision is lost at the retinal level. Since rodes are more in periphery, the vision there is more light sensitive, enabling to see dimer objects. For example, if you can see a dim star throgh your peripheral vision, it may disappear when you lokk at the image directly since you are moving the image to cone rich fovea region which is less light sensitive. As we know cones are associated with visual resolution and rodes are better motion sensors. So with your peripheral vision, you can detect motion better, as it is primarily rod vision.