I bought these to make it easier to see the pins on a CPU that need to be straightened. They aren't really high enough power for that but they are incredible for everyday engineering use. or reading books on the bog as the light has blown

About £15 on Amazon.
Comfortable to wear.
Great eye relief
Wide angle of view
Very good LED illumination
Brilliant build quality
Rechargeable
Only drawback is they aren't that high a magnification but that doesn't matter when marking out - scribing lines etc.
My eyesight is pretty good but these are still a big help - especially where lighting is poor.