MangoFoalix

I kinda feel it all the time, but that's simply because I don't sleep long enough and I'm doing so during the day, as I'm active at night. My sleeping schedule is extremely unhealthy and that combined with looking at the monitor at night makes me feel like a train wreck.  

With that being said, are you sleeping long enough? Also, do you happen to use air conditioner / heaters? Too low humidity may make your eyes dry, which pretty much make them tired, itchy and simply lead to sore eyes.

I sleep somewhat ok. I slept maybe around 6 or so hours tonight. But I am in the same boat as you. I have the worst sleep schedule known to man.

F.lux is a good solution for ling time monitor watching. It make the image warmer as the sun goes down. But it is not an ultimate solution as eyes need to relax, and it is not necessary happen by sleeping.
However, sleeping is an other thing that need to happen...at least 8 hours.