Reduction in Accommodative Response of Schoolchildren by a Double-Mirror System

Purpose: This study first proposed the application of a double-mirror system (DMS) to extend viewing distance and investigate the accommodative response of schoolchildren under a DMS. Method: Fifty-seven subjects aged between 7 and 12 years old were recruited in this study, and the experiment was divided into two stages. The first stage consisted of a case history inquiry, a refraction state, and a visual function examination. In the second stage, the subjects gazed at an object at distances of 0.4 m, 2.285 m, and through a DMS, respectively, and their accommodative responses were measured using an open-field autorefractor. Results: There was no significant difference in the schoolchildren's accommodative response between subjects gazing at an object at 2.285 m (0.14 +/- 0.35 D, p > 0.05) and those gazing at it through a DMS (0.20 +/- 0.35 D). However, their accommodative response showed a significant difference between subjects gazing at an object at 0.4 m and 2.285 m and those gazing at it at 0.4 m and through a DMS. Conclusion: In this experiment, the results of the children's accommodative response measured at 2.285 m or through a DMS are very similar. The viewing distance can be extended by a DMS, resulting in accommodative relaxation. This result may have potential applications in myopia control.