
I can't use contacts. Before I had a corrective operation my prescription was up to a 36. What that meant was that at a 1m distance things seemed 36cm apart. My strongest glasses were "only" 14 on each eye... 18mms thick at the outside, 2mm thick at the inside (and that was with high-index polymer)... had to custom-order them from the Institute of Optometry at Elephant and Castle in London.
Bad eyesight sucks. What's irritating for me is that both eyes are "optically" ok, so both eyes can see just fine without glasses... I just can't point them both in the same direction
Thankfully post-operation I was sans glasses for a year, and now I'm only on a 4 total (and on a good morning with a strong cup of coffee I don't need them at all)

The "invisible" glasses are *great* for those of us who have to wear glasses.
Cheers,
Refractor