Most basic diy lens / shrink glass with uv
4684222 If you read this patent from google patents , you will learn the most basic anamorphic lens making technology.
This is from Corning Glass dated 1987.
There are some glasses which turn to opac state with uv light .
When they are going to opac , they shrink.
You have to make a circular mask and put on to the flat special glass.
Glass is cut circular and there is a circular glass zone around the circular masked glass.
All glass is flat piece and no molded , no grinded.
When you put actinic uv light on to the unmasked glass zone , it turns to opac and shrink.
When around of masked glass circle shrinked , the central area turns to bumped glass and become a lens.
i think this can be applied to plastics also.
Mustafa Umut Sarac