I had Lasik 10 years ago right now (then age 51), which was 2 weeks prior to taking the OW course. I kept my eyes closed for all the no mask drills (I do anyway today in the pool as I hate chlorine). You have to wear the super dark sun glasses outside for a week. For several months I had some "fog" around street lights when driving at night (it did clear up). As for diving after that, the only problem was that before the surgery I was near-sighted. When snorkeling, the mask in the water caused me to see perfectly underwater. Since I had needed reading glasses for eight years before that, my now almost 20-20 vision caused my vision underwater to be about the same as topside--ei., I would need reading glasses to see small numbers on dive computers/gauges, similar to reading a newspaper topside (other than in bright sunlight). I tried the stick-on "bifocals" in the mask and didn't like them. They either fell out or I wound up just looking through one since I felt they were just awkward. So, I have a dive computer that has nice big numbers. I have memorized my analog gauges for depth, PSI and water temp., so I don't have to see precisely what is what (it's not a risk--for example I can tell you that I am down 93 feet and I have a little more than 1500 PSI). My compass is easily readable, though I really have to strain to see the numerical headings (I rarely use them anyway--I head SSW or SE, etc.). Going this route for me, is better than the fuss and cost of a prescription mask. One of my eyes is a little off from 20-20, so everything at every distance is very slightly out of focus-- sort of like jagged edges. But it is so slight that they advised not to go for a free "touch up" as it could make things worse. All in all, it's a million times better than those *&^%ing glasses for 40 years......