I use some clip on magnifiers that fit over my regular glasses. They fit low on the lens and act similar to bifocals, and I can look over the top of them to see with normal vision. They do not protrude more than 1/2" from my glasses and they flip up out of the way when not needed. They are called Magni Clips and come in 2x,3x,4x and 5x. For most rigging work I use the 3x with my glasses I use for computer work. For more detailed the 4x is great. The 5x puts the focal point too close to my eyes and only one eye is used causing a loss of depth perception. The 2x is pretty weak. I'm not affiliated with the manufacturer just a happy user!
Tom