What is the cost of photo-chromic dye?

The manufacturing cost for a factory in Asia, including the cost of materials, is about 4 US Dollars per pair. The factories will then sell the lenses to distributors who buy them at about 6 to 8 USD per pair. Opticians in the US or UK will then pay anywhere from 15 to 100 USD per pair. Retail costs range can range from $50 well into the hundreds of dollars. Photochromic lenses are pretty much the most expensive lenses you can get. The free lenses generally offered when you buy a set of frames cost about 20 cents to make.