They also measured pupil size.  I would like to know if the pupil size
changed.  If it got smaller, it may have resulted in a slight increase
in depth of field.

No.   Just as valid to assume that warmth gave the ciliary muscle a
little extra range of motion so that the total amplitude increased. Or
that the warmth made accommodation more accurate and the usual lag
disappeared.  Given that the study said near VA improved, it seems that
total amplitude increased, not just a moving around of amplitude.
Although, in pre presbyopic subjects increasing amplitude should not
increase VA  (principle of enough is enough and more is not better).
Maybe the warmth decreased pupil size and increased
depth of focus.

Anyway, the only way you could say that pseudo myopia was decreased
would be if the researchers had measured distance refraction pre and
post treatment.  They didn't do that so it is not possible to say
whether it was affected or not.

Dr Judy

Where would you assume the accommodative amplitudes went,
or--conversely--that the post-warming amplitudes came from?

It seems a reasonable hypothesis that--since the periocular warming
returns some AA--they were "locked up" in some kind of "short-term
hypertonicity" (ie, cramp/spasm), no?

I fail to see how this study relates to the thread title of pseudo
myopia and accommodative spasm.  The warming increased accommodative
amplitude and near acuity slightly but the study authors did not
measure far acuity, far refraction, accommodative facility or
accommodative spasm so this study has nothing to say about
pseudomyopia.

Dr Judy

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=1
5885788&dopt=Abstract

Safe ... effective ... proven.  No risk of double vision.  You can
buy/make a corn/rice bag and microwave it....

The effect of periocular warming on accommodation.

   * Takahashi Y,
   * Igaki M,
   * Suzuki A,
   * Takahashi G,
   * Dogru M,
   * Tsubota K.

Department of Ophthalmology, Jikei University School of Medicine,
Tokyo, Japan. genichirot@aol.com

PURPOSE: To investigate the effect of periocular warming on
accommodation amplitude and near vision after prolonged near work in
visual display terminal (VDT) workers in an office setting. DESIGN:
Prospective interventional observational case series. PARTICIPANTS: Ten
healthy Japanese male volunteers (mean age, 39.3+/-2 years [range,
36-43]) with a best distance corrected visual acuity (VA) of >20/20 who
performed near work for 7 hours were included in the study. MAIN
OUTCOME MEASURES: The differences of subjective and objective
accommodations, near acuity, and pupil diameters were compared and
studied in 2 experimental settings with and without periocular warming.
METHODS: Two experiments were performed on each subject on 2 different
days. In one experiment, the subjects wore an eye mask and closed their
eyelids for 10 minutes after 7 hours of VDT work (lid closure [LC]
group). In the other experiment, the subjects applied warming sheets
(WSs) to their eyelids and the periocular region and wore masks for 10
minutes again after 7 hours of VDT work (WS group). Visual display
terminal work was performed under the same settings on both days.
Subjective and objective accommodations, near vision, and pupil
diameters were measured immediately before and immediately after the
resting or warming procedure and again 90 minutes after the resting or
warming procedures. RESULTS: Fifty percent of eyes had an increase in
the accommodation amplitude of at least 0.5 diopters immediately after
application of the WSs. Forty percent of eyes still maintained the
accommodation amplitude level at 90 minutes. The mean near logarithm of
the minimum angle of resolution VA immediately after application of WSs
and at 90 minutes significantly improved relative to the near acuity
values after simple eyelid closure. CONCLUSION: Periocular warming was
found to be associated with increases in subjective and objective
accommodations, with a concomitant improvement in near VA. Periocular
warming with disposable WSs is a simple and effective method of
increasing near work-related ergonomy.