Ah, thats good to know, thanks miller745.
I'd read the bit about review by opthalmologist, and thought 'well that'll be my next port of call then', but I guess as I don't foresee ever needing class 1, then class 2 it is. An odd arrangement of requirements, I'd say, but there.
I spoke to an optometrist friend, he suggested that astigmatism is potentially a problem if it gets progressively worse, as it could be a sign of underlying problems. According to my prescription history, mine is improving slightly over the years, maybe that's the sort of fact that an opthalmologist review would want to clarify.
No idea how I missed the thread you suggested; maybe because it initially began with a discussion about lasik.
Thanks again,
R