Using a lens made of a higher index material for high minus lenses will have what effect on the edge thickness?

Using a lens made of a higher index material for high minus lenses will reduce the edge thickness. Higher index materials have a greater ability to bend light, which allows for thinner lens designs, particularly beneficial in high minus prescriptions.

When a lens has a higher refractive index, the same prescription power can be achieved with less physical thickness. This is particularly important in minus lenses where the center is thicker than the edges. By effectively refracting light more efficiently, higher index glasses decrease the overall diameter of the lens required to achieve the desired optical power, thereby reducing the edge thickness.

In practical terms, when creating high minus lenses, choosing a material with a higher refractive index results in a more aesthetically pleasing, lighter lens with less distortion around the edge, making it a preferred choice for patients needing stronger prescriptions.