freedc,
sad truth, and obviously shared by many of us.
I have over 10 years of U/W "solutions" since that very first every visit to the optometrist at age 42. and very sorry, but the really sad truth is it's a mildly slippery slope from here on out - your eyes will likely continue to slowly degrade, mine have.
when I started asking around our dive club like you have here, I realized the many of the folks I'd been buddying with claimed they could read their gauges but they certainly could not read mine. Have added that to my buddy check "what's my computer read?"
I started with the stick-on's, they are a great place to figure out mask position and magnification. tried lots of different configurations, different mags, 2 different mags (hi/lo) on one side, etc. there are smaller (cheaper) versions than diveoptix, search on "optx 20 20 stick-on bifocals" - and agree with all the "religiously follow directions" from earlier posts, that and waiting several days, as well as being very careful with hot water rinses will keep them on your mask for a very long time.
Next option were "look down masks" (aka "guage readers") described earlier with built-in magnifiers as part of the mfgr'd mask lens: a) few skirt options so they don't fit all faces - like mine, b) they follow a book-reading bi-focal paradigm putting the lenses in the very bottom so you have to crank your head way back to see anything in front of or above you, and c) if poor fit, you end up with a couple of table spoons of water in the bottom of the mask right at the magnifiers ... net-net, didn't work for me but the folks I sold them to seemed very happy to get them...
Next were drop-in replacement lenses, they are a great direction but the vast majority of the corrective lens market is for those other folks needing negative diopters, only a few manufacturers had positive magnifiers in any selection. this has improved dramatically probably due to our aging demographic. If you aren't buying a new mask turn keyed with the lenses, find a local shop that will absolutely positively warranty the conversion and then pay them to do it, otherwise you're out both the mask and the lenses if something breaks (happened to me...). bottom line with this option is you have to decide where you are going to compromise your vision, too much mag to see you camera and your gauge/computer and you may not won't see much else...practice with stick-on's at that mag directly in your primary field of view before buying.
My current "solution" is a $350+mask custom set of ground trifocal lenses glued into my favorite perfectly fitting mask. Found an optician who is a diver (as well as shooter so understands special needs), went in with my reg/gauges, computer, cameras and my wrist mounted compass (he loved all that! had me lay on the floor and measured distances to everything). My large main central field is lightly magnified targeting perfect vision @ 4-6' focal distance but doesn't sacrifice too much beyond that (that fabulous whale shark 30' away was very much in focus but hunting for hammerheads at the edge of the 90-120' visibility was probably compromised), the bottom magnifier is similar to my reading prescription targeting 15-24" focal length allowing me to read everything on my camera. The small top magnifying portion positioned just above the usual field of view targets a tight 8" focal length so for the first in a decade I can read a compass heading through the side window of my wrist mounted compass while swimming it!
only down side with glued in lenses is long term adhesion, prior posters are on the mark here - I had a dive master stuff my mask in my fin's foot pocket and now both glued in lenses have started to come off. they can be glued back in - as long as I don't loose them or they don't break when they eventually come loose. Still would do it again with glue-ins over custom ground replacement lenses and possibly end up with a leaky mask that no one in the chain will take responsibility for...
bottom line, it was the best $350 I've spent on dive gear in a very long time. Made a huge difference in the fun factor. And on the very first dive with them, I spotted a dozen pacific spiny lumpsuckers on a single dive, they're a very difficult marble sized fish to find here in the chilly NW - finding one is truly great, 2 is amazing, a dozen...well...I have the pictures to prove it.
good luck.
ps, and remember if you can't see with a magnified mask in air, you won't be able to see any better underwater, water may change the gross magnification (remember -everything looks bigger/closer) but not what correction your eye's need to see. I had 2 respected shops try to tell me that everything would be better once I had a magnified mask underwater...