From personal experience.
As long as your eyes go bad after half way through course ($$$ remember) and you can be corrected back to 6/6 vision, then you can get corrective glasses/contacts. You had to join with 6/6 and experience degradation later.
Not sure of current policy but this was applicable a few years back.
Re-iterate RG's post. There are 2 laser surgery techniques and one of them disqualifies you for life IIRC. The other technique is allowed after RAAF Medical approval.
HTH