« Return to Course Catalog

Light and Sight: The Science of Vision

Course registration will be available for this course once it is scheduled.

Course Description

What is light? How does it encode information about the world around us? What are our eyes made of, and how do they record images? How do those images get converted into brain signals? These are the questions guiding our exploration.

Every experience you've ever had has relied on a group of special nerve cells devoted to responding to external stimuli. These cells, called sensory receptors, are found in our skin, eyes, ears, nose, and tongue and allow us to make sense of the world. However, with over 70% of all our sensory receptors located in our eyes alone, humans are profoundly visual creatures. Human eyes are powerful detectors of light with near single-photon sensitivity, and almost completely diffraction-limited resolution. In this course, we will explore the quantum weirdness of light and dissect eyes, both literally and figuratively, as we discover how images are created in our eyes and sent to our brains. Join us as we explore vision and gain a new perspective on perception.

Light is one of the strangest things found in nature, at times behaving like the waves from a pebble tossed into a pond, while at other times behaving far more like the pebble itself. We will expose light's quantum weirdness through a variety of physical phenomena including reflection, refraction, diffraction, absorption, and creation in sources ranging from light bulbs to the sun. Every photon of light carries tremendous information about how it was created and where it has been. As we explore the ways light interacts with the world around us, we will pay special attention to how our eyes have evolved to capture as much of this information from light as possible.

Equipped with a bit of intuition on how light works, we then begin to see how our eyes collect, absorb, and interpret the information stored in light. To do this, we will examine our eyes at several different scales of nature, from the macro scale of lenses and pupils, to the cellular scale of light absorbing retinas, all the way to the molecular scale of neural signals. Cameras will be used in analogy with our eyes' function and construction at the macro scale. We will discover the origins of our sensation of color at the cellular scale and see how modern computer screens take advantage of this to trick our brains into seeing colors that aren't really there. Finally, at the molecular scale, we will see how our eyes package and ship information from absorbed light to our brains through our neurons' use of action potentials.

Throughout the course we will focus on the experimental nature of science as much as possible. As always, seeing is believing, and that is never more true than in a course about visual perception. We will play with lenses, diffraction patterns, and light spectrometers, as well as dissect actual sheep eyeballs and measure the speed of neural signals in earthworms. The only prerequisites are an inquisitive mind and a willingness to learn. See the world through new eyes with an enhanced understanding of human vision that will follow you through all future studies, science or otherwise.

Prerequisites: Completion of a high school biology course is recommended.