The light from electronic devices definitely alters your circadian rhythm. UV and blue/purple light is the worst. I don't know if it actually suppresses REM, or just delays melatonin production, in general. If it just delays melatonin, it wouldn't directly relate to REM. For example, supplementing melatonin does not immediately increase your REM.

I guess the opposite of using a computer late at night would be locking yourself in darkness during the day. Or, only use lights in the red/yellow spectrum. Less extreme would be to dim all your lights, or even switch over to candle and fire light as soon as the sun goes down.

Anybody know how this actually works?