I know exactly how your mom feels. Crappy monitors and cheapo flourescents are nightmare for me. I'm not sure it is a condition so much as it is a combination of the frequency of the light and the way people's eyes work. When I try to focus under these conditions, I find my eyes following the twitches, so that the muscles are working overtime to stay on target and stay focused..resulting in painfully sore eyes and then a headache. Because your mom only has one eye to work with in the first place, it is already overworked, so the effects from unsteady light could be even worse. The important thing to note, is that this is not about the electricity, but about the light.