How We See

IMG_5726During this class we play tricks on our eyes, having fun with optical illusions. We make Zoetropes, Op Illusion Cubes, Thaumatropes, and 3D Hand Drawings. We learn about human eye anatomy and how the eye, brain, and optic nerve work together to see images. We compare differences in rods and cones between human vision and night creature vision, learning how a reflective lens called the “tapetum” benefits nocturnal animals. We use magnifying glasses and enlarged examples of color printed images to see that printed images are just made up of cyan, magenta, yellow and black dots.


Benham's Disk. Why do we see color when the black and white disk spins?

Benham’s Disk. Why do we see color when the black and white disk spins?

Benham’s Disk: Lesson coming soon.



3D Hand: Trace hand on black paper with white pencil or on white paper with black pencil. Use ruler to make straight lines around hand. Then make arched lines on hand. Go over lines with patterns of color.

Eye Anatomy: On a piece of masking tape, draw a pattern of black lines for rods (see gray colors) and red, blue and green triangles for cones (how we see color in our eye). Place the tape on a strip of white paper and place it inside a clear plastic container with the pattern facing out. Then layer from bottom up: a white circle, colored circle for iris, then black circle for pupil (The pupil gets bigger in dim light and smaller in bright light). Put a piece of contact paper on top to be the cornea. Place this part of the eye on top of the lid (lens). Add brown cardboard cut out over the top for the eye-lid. Draw red and blue lines with sharpies on the under side of the lid to be blood vessels. Draw red and blue lines across the bottom of the cup to be the optic nerve, which takes the information of what eye sees to the brain. In nocturnal animals, they have more rods and less cones, and a 2nd lens called a tapetum, which reflects light that comes into the eye.