Gurm It's the tint. Theraspecs are nothing special, they're just high-quality tinted glasses. 47 is the color number - there are lots of others. There are green ones for people who work with LED grow lights all day, and red ones for people who work with medical lasers.
Do you know what the tint is supposed to do? An optometrist proposed me a solution which costs ~ $ 400 with a basic frame: Nikon lenses cutting blue light with the possibility of adding a tint and maybe a transition to sunglasses. The lenses look completely different from the crappy orange googles I had purchased for 10 bucks on Amazon. They appear very clear, so I guess the mechanism by which they filter the blue is different (probably some anti-reflective coating). The guy recommended a pink tint, however, he was unable to provide a plausible scientific/technical reason for the choice. I thanked and said I will think about it.
I then read the article posted by @tfouto
I really do not get from the shown transmission curves of the pinky and gray lenses why one or the other would work better against fluorescent light. They do not seem to target any specific wavelength. Does anyone know?
Do they just help photophobic patients, who benefit from reduced light intensity being still able to read clearly, or patients with...what was it called, Irlen syndrome?
I will visit an eye doctor, possibly tomorrow, to get her/his opinion too, but any thought/insight is appreciated. Given how vulnerable to fluorescent light my eyes have become, I am tempted to purchase but I would not want to spend half a grand on something useless. Thanks!