If your vision decline is due to cataracts, don't fight the lense replacement surgery...! I fought it for several years and experienced the same issues you have described. The surgery is magic... zero pain and immediate results! Get a well experienced Doc and "get 'er done"!! You won't be sorry!
Tying the fly on is the biggest issue fo me. I can still tie knots pretty well even with poor eyesight. I do a lot of chironomid fishing in the spring. What I do before I go fishing is add tippet to a few of the flies I plan to use then roll them on a small piece of pipe insulation. This eliminates having to struggle trying go tie flies while out on the water. Ok, all you young bucks can stop laughing now because you'll be there someday.....
Let me second this motion. Two years ago I had cataract surgery and a "new world" opened up. At 62, I could see the colors of all my nymphs again and slip the smallest tippets into size 20 chironomids eyes. If you have not had this surgery yet, make the appointment with your eye doctor this week!
Flip focals. You get used to where to hold things so you can see them. They beat reading glasses. They don't look cool, but you're old, who gives a damn. I tried a magnetic v-grooved threader too, I'd give it to you if I could find it.
I think that I tried just about everything out there over time. Nothing beats a good pair of glasses. And I don't mean Beer glasses.
I am with old man. Seems my near vision has gone south the past few years. I used the flip downs but as mentioned above they always seemed to be in an awkward position. I broke down and bought prescription sun glasses with bifocals and the problem seems to be solved. They are also the best sunglasses I have owned. I also have one of the threaders when I am fishing 18-22's, but going that small is pretty rare in the places I fish.
I went fishing yesterday and forgot the glasses, I only fished for 3 hours as I got tired of the struggle without the glasses. I just have 1.0x or 1.5x quicky grocery store glasses, but I now know I do need them for tying flys. stabbing the eye is easy but watching the threads not so much. I had 20/10 vision, last time I went in for the eye exam, the doc was happy to tell me I had 20/20 vision. I told him that it sucked by comparison..
I had to move up from bifocals to trifocals for tying flies and knots. The closeup lens has made all the difference when it comes to tying on fine leader and small patterns. If you're already wearing bifocals, you may as well belly up to the bar and go with the trifocals -- if you're having problems up close than you need them.
Lost the vision in my left eye to Glaucoma a few years ago. One eye = no depth perception!! My vision in my right eye is ok. Tying on flies was almost impossible I almost quit fishing out of frustration. Then I discovered the replacement threaders and I was back in action.
I know what thats like. Driving at night is tougher. Have to quit fishing before dark and plan my drive time home. Having surgery on Monday to remove fluid in the right eye to relieve the pressure. Last 6 steroid injections in the right eye have not worked. Hopefully this will help keep my vision a little longer.
Go see a good eye doc. If cataracts is not the problem, investigate Lasik surgery. They've been doing it long enough, they have it down pat, and the price has come down. Way down.
This thread made me chuckle. After 6 months of winter steelhead fishing - tying 2 - 4in. flies, tying flies on with 10-12lb. Maxima, all of which I can do without glasses. Now I'm tying trout flies, sz 16-20 and tying up leaders using 5X-7X tippet. I need to wear cheaters for tying, and while trying to tye a blood knot with 6X I can't even feel the tippet materail in my fingers much less see it. Now I can't leave the house without 3 pairs of glasses. Sunglasses, cheaters and prescription glasses for driving at night.