How is your eyesight in any case?
6/60 (class 3) is basically being able to see the top letter on the snellen chart (that "poster blu-tacked...") without glasses. If you can't see that, then you won't get in. But if other people don't find your glasses "that strong", I doubt your vision is that bad, and would guess you're perhaps in class 2 or above.
There are other things taken into account obviously, colour vision being important, 3d vision (not so, for most jobs) etc.
But don't get too worried.