VISION A simple definition of LIGHT is visually perceived radiant energy. This visible light is a small part of the ELECTROMAGNETIC SPECTRUM and ranges in wavelengths from 380 nm to 780 nm. Light is what energizes our visual system. Light reflected from objects into our eyes enables us to see.Lightwaves enter the human eye and send signals along the optic nerve.Light enters the eye through the pupil, is focused on the retina, and is transmitted to our brain via the optic nerve. A significant part of our brain is dedicated to the processing of visual information. Of all creatures on this earth, the human visual system is the most impressive. Birds may have sharper vision, felines may be more sensitive to motion, and horses may have almost a 360-degree field of view, but nothing can beat the combination of features humans possess. The human eye allows good depth perception, excellent color perception, reasonable motion detection, and great visual acuity. PERCEPTION...