I have lousy eyesight - something like -6.5, so when I first saw the blurb for this mask, I went to the web site and registered for a demo mask since I'm an instructor. It took a while to it get to a local optometrist, and the mask was an object of wonderment there since no one in the office was a diver, but some months after I jumped through the hoops, I had one.
I used the mask in a pool and also on some dives in southern Florida and one on Grand Turk. My two major concerns were finding the dive boat after the dive and wondering what the 2.0 diopter difference between my myopia and the mask's -4.5 would be - when I got my mask in the summer, there was n empty monocle. When I worked in the Hydrooptix booth at DEMA in October in Miami Beach, they were shipping the mask with a corrective lens in the monocle. It's a little awkward to use, but I could find the boat on Grand Turk when I surfaced, although you sure feel like Colonel Klink using it, plus you sure don't want to lose that monocle.
I was not comfortable in very clear water - viz around 100' with the fuzziness casued by the correction gap. In murkier water where you're not seeing any great distance, I didn't have this problem. One ongoing annoyance is that when you look straight down, whatever water is in the mask gathers there in the bottom of the spheres. The two purge valves were nice and worked well, but there's always some water in there.
If I pop for the lasik surgery, there is no way I would put contacts back in to let me use this mask, but at my next eye doctor visit, I'm going to get some cheap disposable contacts that will balance out the difference between my eyes and the mask.
I love the construction of the mask, and the polycarbonate lenses would be handy wreck diving at night where I almost broke my regular mask swimming into a small piece of protuding pipe I didn't see in time.
I pretty much use another mask that I got at DEMA - a SeaVision with the red lenses and the 2.0 gauge readers ground into the bottom of the lenses. Even at night, I love this thing since I can actually read my computer and pressure gauge without all sorts of gyrations. Although I'm going to try th corrective contacts, it will still be a hassle wearing eyeglasses on a boat and having to put in some weak -2.0's to use the mask. Let's see - do I wear regular glasses and use -2.0 lenses; wear -2.0 contacts and a pair of -4.5 glasses; just wear regular contacts and use a normal mask? Ah, decisions, decisions. Diving on a nice big dive boat will be a factor here - it's too easy to misplace glasses on a six-pack.
Hey, if you're a -4.5 myope - you might enjoy this mask.