feeling strange while playing half life 2

I had the same till I changed the Fov to 90. Metro 2033 is even worse with an Fov of 45!

I've had that a couple of times, but the main game I remember having bad nausea was Metroid Prime. Which was weird because as far as I remember, that game was pretty slow-paced.

I can only think of my eyes being really annoyed with the Halo 3 FOV.

To be honest, I played HL 1 10 years ago when I was in primary school. I felt dizzy. Even 3 years ago, when I played modern warfare 2, in some maps I still felt dizzy. I did some research. Because our eyes look at the screen as the whole view of our real world and our brain thinks that we are really in that game. When the view in screen moves too fast and our arms and legs don't move at the same time, our brain cannot tell what situation we are in and cannot adjust the body movement to catch the view seen by our eyes. Then our brain makes some signals like headache or nausea to tell us this is not good and we need to get rid of this situation as soon as possible. Also, I heard that by some kind of self exercise, you can go over it and play the same game without any problem.

Isn't it the music? I often turn music and other constantly playing sounds off when I start to feel bad from playing a game. Always helps.

yeah,i use POV everyday
from bluetube and youjazz

You never felt that when riding a car or something? It's probably motion sickness. I've heard you can have it while playing video games too. There are people who can't play Hotline Miami because of that.