Hi all,

I need to make two models of reading glass lens.  One is 1.75 diopter the other 2.5.  Client wants to use aspherical lens surface curvature due to limitataions of thickness.

-help-

He has provided the formula but I can't seem to get it to work.  I don't work often enough in the surface world and I know this is a factor in not seeing my errors.

=R-(R^2-r^2)^0.5+Br^4

Even if you can help without the formula and create 1.75 ashperical, then that would be great and using that example I can do the rest of the work.

Many thanks in adance