Musica

Well, that's a bag of wank.  Mine are still OK, but you're not the first to report this, or some sort of crazy starring on the inner lens.

I'm kind of assuming that at some point I'll need to disassemble mine and clean them, or replace the inner lens with bits of PETG.

I inspected the other lens too and found star shapes as well

Never taken them apart before but they are useless now so found they are pretty easy to pop apart. Was a gift for my xmas and 20 quid isn't expensive but used less than 10 times I am disappointed.

I read some guff about drying them out then sealing with silicone. Fek that

You can replace those inner lenses with any clear plastic.  I'd go with 0.75mm thickness of PETG. A5 will be more than sufficient for one pair:

https://www.ebay.co.uk/itm/201795255973

If you need to replace the tape, I'd suggest 2mm thick double sided black foam tape.  Just cut it into a thin strip and run it round the edge, being sure to butt it up against itself at the join so as not to leave a gap.

https://www.ebay.co.uk/itm/253777592497