SBQ - Magnifying glass

Have you ever used a magnifying glass with your stitching? If so, do you find it helpful?

I've never needed one for the stitching thankfully. My eyes have mostly held up under the strain. I have been tempted on occasion to use one for the actual charts, because sometimes even with a good light, it's hard to tell similar symbols apart, especially ones combined with colors. I noticed this again working on a Charles Craft freebie. The symbol for black is a black box, which is nice and clear. However there's another symbol for a dark grey which is black with a dark X inside. Usually they're right next to each other, so you think it's all black. I'm thinking I should stick to black and white charts if I keep having this issue continually crop up.