Yes, I've read it; if I remember right it's a story about the FJ test squadron, featuring a bloke who's a Harrier mate by trade.
You've answered your own question. You need 100% perfect vision to be considered as a pilot; however, you don't need to maintain perfect vision for your entire life to remain a pilot.
The RAF only picks candidates with perfect vision because frankly they can be picky. A lot of it is simple economics; eyesight can start to degrade from your mid-twenties; do you recruit people for 10 years, train them at a cost PER PERSON of nudging £5M, then bin them? Or do you recruit people with perfect eyesight, and accept that maybe 20-25% will eventually degrade to the extent you need to give them contacts or glasses?
So, to set your mind at rest, if you need glasses, or have anything less than 6/6 vision, you can't join. If you get through 2 years' worth of training (for example) and find you slip a bit at your annual medical exam, you'll get given glasses.
Sorry to be the bearer of bad news.