Considering joining after high school, and I have some questions.

I am currently 18 and a senior in high school. I'm not sure If I should join out of high school or go to college and join. I have a couple problems though. My eyes are pretty bad but I'm getting corrective surgery soon, I also have a bit of an under bite, will that affect my eligibility? My uncle retired as a Colonel in the Army and said things can be waived, but can those?