CK, after finishing training. You're then an investment
But the medics have good reasons for their restrictions and you musn't think they are there just to make things awkward for you. They work on the statistics of the risk of your operational effectiveness being affected by the problem, side effects of medication, compatibility with equipment, survivability in a combat situation in dense acrid smoke, etc.
I wore corrective flying spectacles (CFS) for the last 20 years of my flying; when I asked about contact lenses, the (Army) doc said "No probs. When the Apache arrives, most if not all will have to wear them to work the Sight."
I trained many students who wore CFS; don't give up, go for it.