This page of writing could not be viewed and understood if it were not first sensed and then perceived by the brain . Initially your eyes are aroused by the lines and shapes which form this text , thus initiating the process of sensation . Visual sensation , the physiological procedure of gathering and processing light energy , takes place in the eye . During the process , specialised photoreceptor cells in the retina called rods and cones , receive electromagnetic radiation ( light energy ). This sensory energy is then transduced into neural impulses , which are transmitted to the brain via the optic nerve . To complete the experience of seeing this page , your brain then Organises the sensations into familiar contours , shapes , and letters , through the process of perception , Unlike visual sensation which occurs mainly in the eye , visual perception is said and to occur in the neural pathways or brain . " During perception the brain selects relevant sensory material , sorts and Organises this material into meaningful information , and then interprets and translates the information into observable forms . while distinctions are drawn between where and how sensation and perception occur , the two compliment each other , and combine to form our understanding of everything that can be seen . Sensation provides raw sensory material , and perception uses that material to create a mental image of what is occurring . Without the perceptual process , what you see would be indistinguishable and senseless , similarly if sensation did not occur there would be nothing from which to form a perception .