Half-Life 2 Causes Motion Sickness (Updated)

I felt particularly "whimpy" feeling sick after watching Half-Life 2the first time, and I have felt that way after playing for a long time (well over an hour) a couple of other times as well... Seems I'm not alone. The suspect? Narrowed FOV (field of vision). Apparently normal human vision is around 180 degrees, in Half-Life 2, it's set to 75 degrees (Counter Strike: Source is set to 90). So in effect, you're running around with tunnel vision. It's an interesting read.

See also: here, here, and here.

Update: Even CNET is covering the story!

From the CNET forum: The reason people get motion sickness from playing half life 2 more often than in other games is that it has an uncommon field of view (fov) this is the angle of how many degrees the player can see from side to side on screen at one time. Most First Person Shooter games have a fov of 90 degrees. The default in Half Life 2 is 75 degrees. In effect, Half Life 2 is slightly more "zoomed in" than other games. For experienced gamers used to the standard 90 degrees, the different field of view can be disorienting causing motion sickness. The way to solve this problem is to change Half Life 2’s fov to 90. Go into options and go to keyboard, hit advanced options and enable the developer console “~” then go back into the game and press the tilde “~” key to enter the console. Type these commands:

sv_cheats 1
fov 90

To return the fov back to default enter fov 0 into the console.