Bad medicine - the 'within limits' is the key point here. I think Alec went a step to far when he said 'any corrected vision is an immediate disqualification' but as he correctly stated, you do need to be AVR 1. Here is a link to the standards -
http://www.oaansw.com.au/visionstds/...s_Aviation.pdf
I was deemed medically unfit for all aircrew positions due to my eyesight following flight scrrening. I never wear glasses, but I have a Myopic Astigmatism of -1.25 in my right eye only, perfect in my left. I am corrected to better than 20/20.