Note for those not following long, drawn out discussion: $12.95 is not titanium. Hecho en Chine. Zenni optical (just a thus-far satisfied customer).
Ordering sunglasses (tinted prescription lens) slowed the order down (took 20 days, not 14). Those seem fine.
Now that the (non-tinted) magnifiers are here, a report. I'm generally pleased. I ordered this set as "my prescription, + 5 diopters". I also had someone else measure my inter-pupil distance when I focussed on a point 20cm out - it's a bit closer than the straight-ahead long distance measurement. That should give a nominal "2.25X" magnification (1 + diopter/4), though that's frankly hard to judge. Certainly some degree of magnification, (I easily see things I would not ordinarily notice) and the expected working focus of 20 cm (1/5 of a meter), which is close, but not unworkably close. (your prescription +1 diopter = working focus of ~ 1 meter; +2 diopters, 1/2 meter; +3 diopters, 1/3 meter, etc...).
While I chose to guesstimate it myself based on information here and elsewhere, I'd suggest making use of the approach another poster mentioned; if you have use for this type of thing, mention it to your optometrist when you are getting your regular vision checkup (perhaps even bringing something you might want to work on with you as a test case) and try it out (various diopter additions) on the setup in the optometrists office - easy to change, and you can have them write you a prescription for "special task glasses" if that makes you happy, or if you want to use a vendor that requires a written prescription.