Rods Are Located In The Central Level Of The Nervous System

The first thing that happens when we see something is light is focused onto the retina by the eye. The photoreceptor cells absorb that light. This layer of cells takes the light and converts in into electrochemical signals. There are two types of these cells, rods and cones. Rods are located in the retina, mainly the peripheral regions. Rods are rod-shaped cells and are used for night vision because they respond better to dim light than bright light. This is why people may find that if they look through their peripheral vision, in the dark, they see better than when looking in front of them. Cones are located in the fovea. The fovea is the central portion of the retina. There are three types of cone cells, which depends on how they respond
This network of interneurons goes through the second and third layers of the retina. The third layer of the retina is composed of ganglion cells. The neurons in these two layers, of the retina, contain receptive fields, that are complex, that allow them to be able and see a change in an image. The ganglion cells then use this information to send an output through the optic nerve and into the brain. The function of the optic nerve is to transfer information through the thalamus and into the cerebral cortex. The cerebral cortex is where the process of visual perception is located. The optic nerve also transfers information that is used for the important mechanics of vision. These mechanics are in two different places in the brain stem. The first site is the pretectum. The pretectum controls the size of the pupil, which is determined by light intensity. The second site is the superior colliculus. The superior colliculus moves the eyes in small movements. These small movements are called saccades ("How Vision
The cells in the primary visual cortex are arranged in such a way that they allow the visual system of the brain to detect where objects are. First off, the cells are organized in a way that is called retinotopically. Basically, this means that there is a map located from the retina to the primary visual cortex. The “map” also extends to other areas in the retina that correspond with their areas in the primary visual cortex. This allows the primary cortex to detect the position of objects in a two dimensional view. The third dimension is laid out in the primary visual cortex by comparing the different signals that come from both eyes. The signals from the eyes are processed and placed into stacks of cells. The stack of cells are the ocular dominance columns. The ocular dominance columns contain a checkerboard-like pattern of connections that go between the both eyes. The position of the object in each eye is what allows us to process