I had some more time to do web-searchs;
For eye ware, in the USA, the most common brandname for Photochromic coated lens is: "Transitions (lens, lenses)".
The optical store where you purchased your "Transitions" coated glasses may have charged you 170.00USD for that optional coating.
Now the interesting news:
The actual cost of the dye used was less than $0.02, the other $169.98 of the price was profit for somebody.
Well, $169.98 - the cost of a skilled technician doing the processing.
"Skilled technician" :: If you can boil a pan of water, you are one of those "Skilled technicians".
Manufacturing tidbit:
The wholesale cost of an item is normally (materials cost) * 10.
The retail cost of an item is normally (wholesale cost) * 10.
Here we have a (materials cost) * 9,000
Now the bad news:
Since at this point in the thread I am still thinking that we can not put the e-ink display into a pan of boiling water ....
The dye (or coating) type to use is UV cured, Photochromatic.
UV cured, Photochromatic materials are relatively new ( less than ten years old) and are still covered by a hopelessly entangled mass of patents.
Note (in general):
You can not patent an idea.
You can patent an implementation of an idea.
The few of the patents I have read so far are very cleverly written to try to pass off the "idea part" as the "implementation part".
Example:
You can not patent: acetylsalicylic acid
But you can patent a little white tablet form of acetylsalicylic acid and call it: Aspirin
The lawyers that are writing these Photochromic dye patents are trying their best to drag all of organic chemistry into the patent exceptions enjoyed by drugs.
Our silent lurker, Jane Tizzy, provided assistance with the chemistry in this post.