Lens weight as a function of density, shape, and power.
An equation to determine the weight of a spherical lens as a function of its density, shape, and power is presented. I found that if center thickness and size are held constant, lens weight increases as the lens power increases in minus or decreases in plus. A way to calculate the power at which two lenses are equal in weight when they differ only in density is also presented. This power is the endpoint of a range of powers above which one of the two lenses is heavier, whereas below this power it is lighter than the other lens. A way to reduce the weight of a lens by altering the surface powers is also suggested.
D005139:Eyeglasses / Q000592:standards*; D006801:Humans; D012029:Refraction, Ocular; D014894:Weights and Measures