Eye Correction Surgery

If I wanted to get eye correction while I was in, at what point would I be able to do this? Someone that I spoke to said that if I wanted the military to pay for any of it, I'd have to wait until I finished my first enlistment term and do it during my second. Any truth to this? Or could I try to stack leave days and do it then? Would it be covered? TLDR; want to get corrective eye surgery. Is there a time limit I have to wait before doing so and will it be covered?