Why do I need glasses for reading if I'm nearsighted? Unless you mean "ignores" nearsightedness and corrects astigmatism only? (Those are what I use for computer use, when I bother to wear them.)
I don't mean literal reading glasses, just apply the same principle: glasses designated to a task, which for most people would be using computer. All prescription glasses are for your "resting" vision to be on far objects. You'd want the resting vision to be on the computer.