Thanks, Midnite! For the first time, I actually sought out a birthday post, because I needed it. Usually I succeed at keeping the birthday at arm's length.
I just determined that it isn't just the monitor whose radiation (in the broad sense of radiation which even includes ordinary light) my nervouis system is reacting to, it's having the computer on in the first place. I wasn't thinking I was especially electro-magnetically sensitive, as MCS patients often are, but it turns out I am.
So keeping the thing off seems to make sense. But then again, I needed to "hear" someone say "Happy birthday"... Sometimes what hurts you sustains you too.