If I were you, I'd get the corrective surgery done anyway (once you're old enough). Even if the surgery does not correct your vision enough to make you eligible for any SOF jobs, you'll be better for it. That minimum age for surgery only gives your eyes time to mature, and gives you time to save up the money and train up for the future (in case the surgery does make you eligible). Just bear in mind that the surgery may not bring your eyesight within the parameters required for SOF. You mentioned that chance yourself. Take that into consideration as you plan for the future.
So don't bank all of your hopes and dreams on Lasik/PRK. If you still want to defend this great nation, then by all means join up. Don't try to "get around" the eyesight issue. Get the surgery done anyway, whether you go SOF or not. Once it's done, then assess if pursuing your dream of SOF is realistic. Hope for the good news, but be prepared for the bad news. There's still honor without the tabs. You just need to find a new 25m target.
I had LASIK done Aug 01 when I was in my late 30's, I went from 20/400 worst eye to 20/10 and 20/12. My distance vision hasn't changed a bit since then, but, I did have to get reading glasses late last year.