You might find the Merkur construction set and its relation to contact lenses very interesting: https://en.m.wikipedia.org/wiki/Otto_Wichterle https://en.m.wiki

You might find the Merkur construction set and its relation to contact lenses very interesting: https://en.m.wikipedia.org/wiki/Otto_Wichterle https://en.m.wikipedia.org/wiki/Otto_Wichterle