My eyesight is definitely still very good, but I _do_ need extra magnification when I'm painting eyeballs on my miniatures because they're so damn tiny (the best technique is to paint the whole eyeball black, then put a white dot at the very left and right so you just have the black in the middle looking like the pupil). I've had a magnifying glass on a arm attached to the side of my painting table for a few years and it helps but even with that I've been finding it tricky, it doesn't quite magnify enough without ending up with the end of the paintbrush awkwardly close to the magnifying glass.
A friend has a set of those headset magnifying thingies, so I looked at a bunch and bought a set for myself, from https://visionaidmagnifier.com. It's got a couple of LEDs in it and there was the choice of a USB-rechargeable one or a 3x AAA battery one, so I went with the latter since I'm very unlikely to need any additional lighting given how brightly lit my painting table is. The handiest bit is that it comes with five different magnification strengths and you can easily swap them out, change the angle, and move them closer or further away from your eyes.