This semester at college I am taking the course known as brain & behavior in other words the study of the brain and how it effects the human body. Currently we are talking a lot about vision in relation to brain and behavior. We have talked about rods which are plentiful in the retina. The rods within the retina react to dull light and are less reactive to to bright day light which bleaches the retina. Cones are mostly in the fovea the central part of the eye. Cones are also less active in faint or dull light and are more active in bright light and are a key component in relation to color vision. Since there is a difference in the amounts of rods and cones people have better color vision in the fovea and less color vision in the periphery. Cones have a more easier route to the brain then do rods. In the fovea the receptors have their own lines to the brain unlike in the periphery were the receptors share with ten to a hundred of other lines together. The ratio of rods to cones differs among different living species such as the South American oilbird which have about 15,000 rods for every cone and their rods are far into the retina to help them to be aware of faint light in the nighttime. Rods and cones both have photopigment chemicals that let out energy when hit by light. Photopigments also contain 11-cis-retinal a derivative of vitamin A and proteins called opsins. The ospins can switch the photopigments sensitivity to various wavelengths of light. Unlike the rods and cones ospins seem to be about the same in abundance to other vertebrates and invertebrates. In this class we have also talked a lot about color vision and the significance of wavelengths. In the human system of vision the smallest visible wave-lengths are seen as violet and more longer wavelengths of color are seen as blue, green, yellow, orange and red. The visible wave-lengths are different among species depending upon the amount of the species receptors. There is a lot of information that I hope to learn about in this type of biology class because it can explain the different human and animal behaviors that occur all the time.