[11:15]

Reflectors

For starters, there doesn't seem to be much in the way of curved guides available on Aliexpress. Actually, it's just this:

Now, because phones are like 75mm, I'm assuming that the reflectors are larger than I need them to be.

The other solution is something like this:

I believe this is a much more accessible method for semi-custom optics. Essentially, it seems to be [Screen]->[lens]->[flat reflector]-[eye]. I think I've got a better chance finding some lenses that will work for this application than a reflector lens, but I won't eliminate the option of spending £30 just to get the curved lenses of the first option. It's just that they look kinda far away:

Smart Glass Film

I expected that it would be a special pane of glass, but there's some affordable film on Aliexpress in a variety of different colours.

The original idea was to have some pane that gave a frosted glass look and another that changed from transparent to black opaque. The thing is that I have some frosted white film and I tried it around my vision, and it doesn't look anywhere near as good as the Windows 11 "start menu panel material" (officially called Mica) as I expected. I'd also expect that I would run into contrast issues. Additionally, this PDLC film is a lot closer to the near opaque Mica material when OFF (it's transparent when ON) than I expected.

It's also cuttable, flexible, self adhesive and allegedly can even block UV, so I think the black tinted film would be a good solution. I can only assume that AR glasses manufacturers haven't adopted it because it needs low current AC power to turn on the film.