The other emitted-photon difference is flashing. If your monitor uses pulse width modulation to dim, any brightness under 100% is going to flash high-frequency

The other emitted-photon difference is flashing. If your monitor uses pulse width modulation to dim, any brightness under 100% is going to flash high-frequency lights at your eyes. Supposedly if this is done fast enough it's not unhealthy, but it's a case of "no solid evidence it's bad for you" plus anecdotal links to headaches. I have personally had drastically fewer screen headaches since leaving my hardware brightness on 100% and lowering brightness via the driver. I'm a believer in the spectrum thing, too. I find halogens way easier on the eyes than ultra-power-saving diodes.