I researched this field for a while back in the early 1990s, which eventually
led to my dissertation being partly on the side effects of playing Doom, namely
Part 2 (NB: if any of you ever used the old Doom cheat codes file, most likely it
was the one I wrote when I ran the DHS and the USENET group); see:
http://www.gamers.org/dhs/diss/
I had hoped to do more when I became head sysadmin at a VR research
centre in 2000, but alas I never had the time, even though I ended up
owning plenty of relevant equipment (high-end SGIs, etc.) Ah well.
Anyway, the best work I could find on these issues back in 1994 was
by Dr. Eugenia M. Kolasinksi at the US Army Research Institute (West
Point). See:
http://www.hitl.washington.edu/scivw/kolasinski/
http://www.psychologyforeliteperformance.com/biography.htm
I had a number of conversations with her about sim sickness issues.
It's a very complex area, so many factors involved, great variance
between individuals, as I quickly discovered with my very limited Doom
study, which ideally should have been much larger, but I lacked the
time, though it was still revealing and interesting nonetheless; those of
you here referring to Doom, Descent, etc., have a look, it'll probably
bring back memories! I asked Eugenia recently about her work back
then; she said it's still a decent resource, though much more has been
done since of course, using newer equipment, techniques, etc.
Possible side effects is one of the reasons Nintendo canned the
Virtual Boy. I tried the VB at NOA's HQ on a visit in 1995; the 3D
effect worked rather well IMO (only wireframe gfx though, so I
didn't think it'd be much of a hit), and I had no problems, but I
guess Nintendo decided the wider risks weren't worth the hassle;
rumour has it the $40M VB budget had originally been intended
for an HMD for the N64, canned for similar reasons, but I couldn't
get that confirmed.
Side effects of various kinds will always be a problem for VR technology.
Extended or excessive use, and/or use by those partcularly prone to relevant
effects, is where the problems will lie. My suggestion was the user should
sign a waiver when they buy such equipment, but that might be complicated
I suppose, and perhaps not valid anyway in some nations. Still, worth a try...
In the end, common sense perhaps? Try it & see; if you don't get side effects,
or if they're tolerable with sensible usage, then buy. Otherwise, don't buy. Let
the market decide and let the user bare the usage responsibility.
Ian.