Ill tell you what I did when I first needed magnifier assistance, and I have been been happy with my vision situation for the last 15 years(im 60 now). I went to my eye doctor, and got a prescription for both far and reading glasses. I didnt really need much as far as distance goes, but a little helped me with the 200 yards plus stuff. I then had my optician craft me a pair of polarized sunglasses with a tiny bifocal/magnifier in the very bottom of the lens. The magnifier is completely out of my line of sight normally, but when I need to tie on a fly (or write down a golf score), I position the fly in the lower field of vision and look thru the bifocal. It works great. Now, these were expensive glasses. But I have worn them constantly when outside or driving and I dont regret spending the money at all, as it has made my life easier.
"Fishermen are born honest, but they get over it"
Ed Zern