VR safety concerns/precautions (reference to paper)

[P3D John W Roberts <roberts@xxxxxxxxxxxxxxxxx>]

>Date: Mon, 29 Apr 1996 15:51:31 -0500
>From: P3D Marvin Jones  <72657.3276@xxxxxxxxxxxxxx>
>Subject: Re: 3D and children's eyes

[Harold Baize:]
>> One last thing,  and I think we may have discussed this when the
>> V-B was introduced, but it comes with a warning that states that
>> the game "MUST NOT be used by children under the age of seven (7)
>> years. Artificial stereo vision displays may not be safe for such
>> children and may cause serious, permanent damage to their vision."
 
>> Note, the caps are from the warning.
>> Is this just Nintendo's way of avoiding nusance law suits or is
>> there some research on the effects of stereo displays that we
>> don't know about. It's hard to imagine it causing "serious"
>> and "permanent" damage!
 
>I imagine that damage, particularly "serious" or  "permanent" damage, is pretty
>unlikely, but you know what it's like when lawyers get involved in writing ad
>copy. Ironically, I remember when 3D comics began circulating back in the early
>'50s the general line was that viewing 3D was beneficial to children's eyesight
>(probably with no more authority than the current negative warnings).

I finally found the article on VR systems and safety: "Binocular Vision in
Stereoscopic Virtual-Reality Systems", by M. Mon-Williams, S. Rushton, and J.P.
Wann, University of Edinburgh, Scotland (ISSN0097-0966X/95/2601-0361-$1.00),
page 361 in the 1995 SID International Symposium - Digest of Technical Papers
(reprints available from the Society for Information Display, 1526 Brookhollow
Dr., Suite 82, Santa Ana, CA 92705-5421). The paper describes the results of
experiments conducted by the authors.

There may be several areas of concern - this particular paper discusses
visual distortions created by the display system, muscular strain, and the
risk of learned decoupling of accommodation and convergence which could lead
to temporary or permanent degradation of stereo vision. "Quality" of the
optics was not a determining factor - a LEEP system caused even more problems
than a cheaper system - but other factors seemed to influence the degree of
problems experienced. To quote briefly from the beginning and end of the paper:

  Abstract: Adverse visual effects may follow use of binocular displays, but
  can be avoided through careful design and removal of stereoscopic disparity.
  Display development is discussed in the light of our research into the
  modification of the reciprocal links between accommodation and vergence when
  conflict exists between image disparity and focal depth.
  ...
  Conclusions: Production of visual deficit through use of virtual reality
  systems is obviously undesirable. The production of short term ocular
  symptoms is unsatisfactory, but of greater concern is the potential for
  a VR user to drive, or operate machinery, with unstable binocular vision
  and a decrease in visual acuity following immersion in a virtual world.
  Another worrying scenario is a child or adult with already unstable binocular
  fusion using a large interval stereoscopic VR display, and suffering
  permanent breakdown of binocular function with the possibility of resultant
  strabismus and diplopia. It is possible to avoid the occurrence of binocular
  vision anomalies after use of virtual displays, but a collaborative effort
  is required between vision researchers and the manufacturers of such displays
  in order to minimise binocular problems.

While a few papers here and there don't necessarily mean that the premise is
accepted as established fact by the entire scientific community, the existence
of this paper and the ones it lists as references indicates that there has
been some serious study on the topic, and there may well be a good reason to
pay attention to studies in this area. Since brain development is much more
active in children, it's not too surprising that there might be particular
concern about children in particular age groups.

Also, remember the history and the current implementation of the Virtual Boy.
It was highly publicized during its development phase, with 
predictions of a date of availability, then things were quiet for a long time,
and the machine appeared on the market many months later than the originally
predicted date - if I recall correctly, it even missed a Christmas sales 
season. I believe it had been reported at the time that there were some
snags in the development. If a reason for the delay was the discovery of a
potential for visual problems, and the time required to find a fix for the
problem, then that would be an example of a company performing a valuable 
service for its customers. The system as it now exists includes the safety
warnings, including age limitations, rest periods, cautions about appearance
of various problems, and a strong insistence that the system interocular 
and focus be adjusted for each user. It would appear that with the 
modifications, the warnings, and the adjustments, the company feels this
display is sufficiently safe for the public to use. It would be a shame
if a user were to dismiss these precautions as probably paranoid.

Note that I'm not saying that all VR systems are guaranteed to make anyone
who uses them look like Ben Turpin. But I get the strong impression that:
 - A VR system isn't something you can just throw together and be confident
   that it won't cause any health problems. Until more is understood, careful
   testing of each new design may be necessary.
 - Some designs may be more likely to cause problems than others.
 - Some people may be more susceptible to VR-induced vision problems than
   others.
 - It's probably a good idea when using a VR system to take sensible
   precautions to prevent or detect early onset of visual problems.

John R


------------------------------