Students will enjoy following in the footsteps of one of the first optometrists-Rene Descartes-as they simulate his “ox eye” experiment. This very effective experiment shows students how the eye's lens and eyeglasses function together to produce clear vision. Students build a model eye and use a light to project a real image of an object on the “retina” of the eye model. Nearsightedness and farsightedness can be simulated and then students experiment with corrective lenses to determine whether a convex or concave lens is needed to remedy the vision problem. A great experiment for both introductory and advanced-level students! An individual kit and a classroom set of four are available. Includes reproducible student handouts, teacher notes, and reusable lenses and eye models. Flashlights for each group are required, but not included in these kits. The Student Flashlight AP6767 is a very economical choice; requires two D-cell batteries.