Where to buy UV clear/dark photochromic fluid (transitions lenses)

I am trying to make a lens that auto-dimms and initially was going to use liquid crystal light valves (turns dark when introduced w/ voltage) but couldn't as my lens was curved and the LCLVs exclusively came in flat glass setups. Someone suggested I check out the material they use in transition lenses so I looked it up but couldn't find any for sale. This prompted a few questions, 1. Does the liquid stain and/or shouldn't be worked with in a garage. 2. Or does it not have a wide enough market to be sold. 3. Or is it a patented recipe that only the transition people own and they choose to not to sell. I am more on the electrical side of things which is why I opted for the LCLVs (was looking for a lens design in a CAD format so I could workshop something, no luck). Thanks in advance! via /r/engineering https://ift.tt/2KzvWHy