This upgraded deluxe Schematic Eye made of metal, is sturdier and more durable. No more sliding out of position!
The back of the Schematic Eye can be adjusted from +3 to –4.5 to simulate different refractive errors. Hypermetropia (farsightedness) is created with the eye set to plus values while Myopia (nearsightedness) will result with minus values. Range can be extended with trial lenses. Plus powers add myopia, minus adds hypermetropia, cylinder lens simulates astigmatism.
The front wells hold up to three trial lenses. Includes instruction. The axis compass on the front indicates angles from 0 to 180 degrees for settings on the trial lenses.