JMIR Publications

ABSTRACT

Background:

Augmented reality (AR) is a technology that superimposes computer graphics on the real world to assist our daily lives. Viewing AR images causes vergence accommodation conflict (VAC) and induces visual discomfort. Maxwellian displays have been hypothesized to prevent VAC, as they can theoretically eliminate accommodation cues completely. However, Maxwellian displays are concerned that accommodation will still occur when viewing AR images in the real world because that are superimposed on the real object.

Objective:

This study investigated the changes in ocular refraction and pupillary diameter when viewing AR images using wearable glasses with a Maxwellian display.

Methods:

Twenty-two healthy young adult volunteers (mean age±standard deviation, 20.7±0.5 years) participated in this study. All participants were instructed to fixate on the center of an asterisk target displayed on both a liquid crystal display (real target) and Maxwellian display (AR target) for 29 s, while wearing the Maxwellian display on their right eye. A binocular-open-view-type autorefractometer was used to continuously measure SE refraction and pupillary diameter of the left eye while the real target was displayed for 3 s. The target was subsequently changed from real view to AR for 13 s, and subsequently from AR to real view for 13 s. Each participant performed this step stimulation 5 times for each distance. Targets were presented sequentially at 5.0, 0.5, 0.33, and 0.2 m. After examining each distance, the participants were asked to indicate which target—the AR or real target—appeared to be in front or in the same position.

Results:

While fixating on the AR target, the accommodative response at 5.0, 0.5, 0.33, 0.2 m were 0.28±0.29 D, −0.12±0.35 D, −0.43±0.57 D, −1.20±0.82 D, respectively. The accommodative response at 5.0 m was significantly more positive than that at 0.33 and 0.2 m (5.0 m vs. 0.33 m, P=.001; 5.0 m vs. 0.2 m, P<.001). The amplitude of pupil constriction at 0.5, 0.5, 0.33, 0.2 m were −0.07±0.22 mm, 0.08±0.17 mm, 0.16±0.20 mm, 0.25±0.24 mm, respectively. The amplitude of pupil constriction at 0.5 m did not significantly differ from constrictions at other distances (0.5 m vs. 0.5 m, P=.175; 0.5 m vs. 0.33 m, P=.64; 0.5 cm vs. 0.2 m, P=.073). The amplitude of accommodation showed a significant negative correlation with the amplitude of pupillary constriction (R2=.187, P<.001). Most participants perceived AR target to be in front of the real target at all distances.

Conclusions:

These findings showed that accommodation works using Maxwellian display and that depends on the distance of the real-world object as a reference. Furthermore, the accommodative response using the Maxwellian display induces an inconsistency with the subjective distance perception in the real world. Clinical Trial: N/A