Aye, age doesn't come itself. I had perfect eyesight through teens, 20s, 30... hit 40 and had to start using 'readers'. Nowadays, I'm on varifocals 24/7 - and they still won't cope with fly tying. That's not a problem though, as all I need is a pair of 4x cheapo 'readers' from Asda/Boots or whoever is doing them. Couple them to a good angle-poise lamp shining over your shoulder, and a decent neutral background card behind the fly.
Don't look up suddenly and expect to see what just happened on the telly, though
Col