vision
36.5 | Vision By the end of this section, you will be able to: Explain how electromagnetic waves differs from sound waves Trace the path of light through the eye to the point of the optic nerve Explain tonic activity as it is manifested in photoreceptors in the retina Vision is the ability to detect light patterns from the outside environment and interpret them into images. Animals are bombarded with sensory information, and the sheer volume of visual information can be problematic. Fortunately, the visual systems of species have evolved to attend to the most-important stimuli. The importance of vision to humans is further substantiated by the fact that about one-third of the human cerebral cortex is dedicated to analyzing and perceiving visual information.