Vision

How are we able to see?

Vision is a very important sense for humans. We use our vision to understand our world, and to understand ourselves. A person in a pitch dark room in unfamiliar surroundings would be quite uncomfortable. A person having to carry a very full cup of coffee without looking at the coffee cup may spill hot coffee all over themselves. But what is it that we see?

As you travel through these web pages on vision, you will be learning about the eye, light, how light affects our eyes, and then how the light information gets carried back to the brain. Some bits of this story should already be familiar to you. For example, you know that light has to pass through the eye's pupil, and that the information from the eye gets carried back toward the brain through the optic nerve (cranial nerve II), passes through the optic chiasm, makes a pitstop in the thalamus, and then runs to the occipital lobe. This stuff you already know.

But, you do not yet know how the eye functions. What are the sensory receptors for light? How do they work? What happens to the light when it enters the eye? The answers to these questions are some of what you'll learn here.

One cute web site to go to for lots of fun vision facts is the Opthamology Guide. You can even find a color blindness test related to what we discussed about color vision in lab.