Vision and Perception

Of all of the senses humans possess, vision is perhaps the one that has fascinated scientists, physicians, and philosophers the longest, well before the field of psychology began its investigation. Exactly how does the eye perceive objects in the distance? Do eyes send out rays or does light enter the eye? How do humans with sight perceive shapes or colors? How can one be sure that the color blue looks the same to one person as it does to another?

For centuries, people raised these questions and many more, but only in the Enlightenment era did humans begin to truly understand the principles behind sight. In more recent years, the field of psychology, in tandem with a greater understanding of light, has discovered many answers about how the eye works. In this topic, you will explore some of the mysteries of vision, learn how this key sense functions to help humans perceive the world, and how your perception can be tricked.

Essential Questions

• What are the key principles of light and how do these influence human vision?
• What are the main parts of the eye and how do they function to collect sensory information to the brain?
• How does the brain interpret visual sensations to create meaningful perceptions of the outside world?
• How do the trichromatic and opponent-process theories of vision combine to help explain how humans perceive color?