Does astigmatism make eyeglasses thicker?

Question

or only change the curvature of the lens?

Answer 1

It should not change the thickness of the lens.  My eyeglasses have a plano lens and a lens to correct astigmatism.  The lens with the prescription is actually thinner than the one with no prescription.

Answer 2

Astigmatism is only a specialised vesrions of short- or long- sight.

It affects the thickness of the lens in the same way as any otehr RX, but only in one meridian.

an Rx like -0.50 DS / -2.50 ax 180 in a round lens would be appreciably thicker at the top and bottom edges that it was in the horizontal.

The power of a lens, spherical or astigmatic, depends on the difference in curvature between the front and back surfaces.

If the overall power is +ve, the centre is thicker than the edge, -ve the other way around.  The larger the Rx, and the lens,  the more obvious the effect.