If you rotate a pair of polarizing sunglasses, you will find that they cut road glare much better in some positions than in others. Pupil Your pupil changes size to control how much light enters your eye. Seeing Your Blind Spot See your blind spot. Seeing Your Retina You can use a dim point of light to cast a shadow of the blood supply of your retina onto the retina itself. This will allow you to see the blood supply of your retina, and even your blind spot.
Soap Bubbles Create geometric art with soap films.
A photometer made by making a grease spot on white paper can be used to compare the brightness of the sun to the brightness of a lamp. By finding a position at which the sun is as bright as the lamp the power output of the sun can be estimated. Spectra Fingerprints for light sources. You can see the spring, but you can't touch it. Water Sphere Lens Make a lens and a magnifying glass by filling a bowl with water.