Assessing vergence-accommodation conflict as a source of discomfort in stereo displays

Transcription

1 Assessing vergence-accommodation conflict as a source of discomfort in stereo displays Joohwan Kim, Takashi Shibata, David Hoffman, Martin Banks University of California, Berkeley * This work is published in Shibata, Kim, Hoffman, & Banks (Journal of Vision, 2011)

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3 Possible causes Crosstalk between two eyes views Binocular asymmetry (brightness, color) Unintended vertical parallax due to head tilt Frame effect Visuo-vestibular conflict Vergence-accommodation conflict

4 Vergence & accommodation: natural viewing

5 Vergence & accommodation: natural viewing vs. stereo viewing

6 Dioptric space

7 Birefringent lens display: structure Adopted from G. Love et al, Opt. Lett., 2009.

8 Birefringent lens display: operation Adopted from G. Love et al, Opt. Lett., 2009.

9 Task and stimuli Angular size: 4.2 Dot density: 43/deg 2 Disparity amplitude: 4 arcmin Spatial frequency: 1~2cpd

10 Task and stimuli Angular size: 4.2 Dot density: 43/deg 2 Disparity amplitude: 4 arcmin Spatial frequency: 1~2cpd

11 Task and stimuli Angular size: 4.2 Dot density: 43/deg 2 Disparity amplitude: 4 arcmin Spatial frequency: 1~2cpd

12 Task and stimuli Angular size: 4.2 Dot density: 43/deg 2 Disparity amplitude: 4 arcmin Spatial frequency: 1~2cpd

13 Task and stimuli Angular size: 4.2 Dot density: 43/deg 2 Disparity amplitude: 4 arcmin Spatial frequency: 1~2cpd

14 Task and stimuli Angular size: 4.2 Dot density: 43/deg 2 Disparity amplitude: 4 arcmin Spatial frequency: 1~2cpd

15 Time flow of the experiment for a day (1) (2) Symptom Questionnair e (3) Symptom Questionnai re Session 1 Session 2 Break (20 minutes) Start (30 minutes) (20 minutes) (4) (5) (6) Sessioncomparison Questionnai re End TIME Two sessions on the same viewing distance

16 Time flow of the experiment for a day (1) (2) Symptom Questionnair e (3) Symptom Questionnai re Session 1 Session 2 Break (20 minutes) Start (30 minutes) (20 minutes) (4) (5) (6) Sessioncomparison Questionnai re End TIME Two sessions on the same viewing distance Two symptom questionnaires

17 Time flow of the experiment for a day (1) (2) Symptom Questionnair e (3) Symptom Questionnai re Session 1 Session 2 Break (20 minutes) Start (30 minutes) (20 minutes) (4) (5) (6) Sessioncomparison Questionnai re End TIME Two sessions on the same viewing distance Two symptom questionnaires One session-comparison questionnaire

18 Symptom questionnaire Questionnaires Session-comparison questionnaire

19 Estimating comfort zone for stereo displays: Experiment 1 Conditions 1,3,5: Cues-inconsistent Stereo-viewing Conditions 2,4,6: Cues-consistent Natural-viewing

20 Participants in Exp participants, aged 19 to 33. Contacts: 11, glasses: 4, normal vision: 9 All observers had normal stereo vision. Every observer completed 6 sessions. All were unaware of experimental hypothesis.

21 Exp. 1, symptom questionnaire * This work is published in Shibata, Kim, Hoffman, & Banks (Journal of Vision, 2011)

22 Exp. 1, session-comparison questionnaire * This work is published in Shibata, Kim, Hoffman, & Banks (Journal of Vision, 2011)

23 Estimating comfort zone for stereo displays: Experiment 2 Conditions 1,3,5: Uncrossed conflict Contents behind the screen Conditions 2,4,6: Crossed conflict Contents in front of the screen

24 Participants in Exp participants, aged 20 to 34. Contacts: 9, glasses: 2, normal vision: 4 All observers had normal stereo vision. Every observer completed 6 sessions. All were unaware of experimental hypothesis.

25 Exp 2, symptom questionnaire * This work is published in Shibata, Kim, Hoffman, & Banks (Journal of Vision, 2011)

26 Exp 2, session-comparison questionnaire * This work is published in Shibata, Kim, Hoffman, & Banks (Journal of Vision, 2011)

27 Optometric comfort zone & our estimation * This work is published in Shibata, Kim, Hoffman, & Banks (Journal of Vision, 2011)

28 Conversions to different units * This work is published in Shibata, Kim, Hoffman, & Banks (Journal of Vision, 2011)

29 Conversions to different units * This work is published in Shibata, Kim, Hoffman, & Banks (Journal of Vision, 2011)

30 Conversions to different units * This work is published in Shibata, Kim, Hoffman, & Banks (Journal of Vision, 2011)

31 Conclusion Vergence-accommodation conflict causes visual fatigue. Viewing distance and sign of conflict affect visual fatigue. The results are useful for designing 3D content and viewing parameters for various display applications.

32 Thanks to... Takashi Shibata David Hoffman Martin Banks Also, thanks to Clifton Schor for valuable advice

33 Vergence & accommodation in various situations

34 Phoria The error of vergence when it is stimulated by accommodation without vergence feedback

35 Relative vergence range Vergence range within which one can maintain clear and fused view of given accommodative stimulus Relative vergence range at 3D of Acc.

36 Optometric comfort zone Percival s: Middle third of ZCSBV Sheard s: Starting from the phoria line, extends onethird towards the relative vergence range on both sides

37 Measured results 24 participants (ages from 19 to 34)