I bought red glasses to limit staying awake too long in the night. These were recommended by the polyphasicsleep blog here:

http://www.polyphasicsociety.com/polyphasic-sleep/adaptation/night-lighting/

I can confirm that I do get sleepy with them on. It doesn't impede my work (though I wonder what graphics people can do).

It helps avoiding doing accidental excessive over hours (I can get into the flow and not notice time until hours later) which led to sleep deprivation (I still do have to get up in the moring) a few times which then ruined overall productivity.

I also installed red lights in one childrens room and switch them on in the evening. Whether that helps is less clear.

EDIT: I followed Dorikkas advice and installed f.lux. Very simple and just works. The effect is not very pronounced esp. so because I have very bright (daylight like) illumination on my desk. Nonetheless the effect alone brings some awareness and also sometimes I don't sit on my desk.

A note about desktop illumination. It was recommended to me much earlier that good ambient daylight-like lighting improves productivity and reduces stress on the eyes. The latter is because bright screens only in an otherwise comparatively dark room stresses the eyes when switching or adjusting between screen and background.