What causes CSNB – What is wrong with the eye?
The cause of CSNB is unknown. On direct and microscopic examination of the eyes there do not appear to be any physical abnormalities to account for the vision problems (Witzel 1978). It is thought that there is a physiologic abnormality in how the retina functions, specifically, in the transmission of impulses between the retinal cells. In order to further understand the problem we need to look more closely at how the retina works. The retina has many cellular layers that interact to process and transmit visual stimuli to the brain. Visual input comes in the form of light. When light strikes the cells in the retina it causes a sequence of electrical events that are transmitted to the brain and eventually interpreted into the image that we see. The first cells that respond to the light are the photoreceptors. There are 2 basic types of photoreceptors; the rods, which function best in dark conditions, and cones which function best in day-light conditions and are also responsible for colo
