Abstract
Purpose :
To evaluate a novel objective method of real-time monitoring of near-work distance and face illuminance of children using mobile devices which included a novel software (app). The fitness of the app for the purpose of extending the children’s habitual near work, which can reduce the eye strain and, potentially, myopia progression is tested.
Methods :
The app was initially calibrated in a lab to confirm the accuracy of distance and illumination measurements, and configured to store average values every 20 seconds in a remote database. Measurements of face-device distance and room illuminance in children were obtained from two schools where tablets were used regularly. Children were divided randomly into a control group CG and intervention group IG. 11 students participated in School #1 (10.6 ± 0.5 years) and 34 in School #2 (11.1 ± 0.7 years). In both groups the app recorded data only when a child’s face was present in the image from the camera. Additionally, in IG the app intervened when the face-device distance was shorter than 40 cm by darkening the screen (active mode) while in the CG group the app just recorded the values without producing any effect on the screen (passive mode).
Results :
The total mean face-device distance was 36.8 ± 5.7 cm in CG and 47.2 ± 6.5 cm in the IG. with statistical difference (p<10-6). Differences in those two groups where also significant within the same school (p<0.001) and no differences were found within the same group from different schools. The total mean classroom face illuminance was 980 ± 350 lx in School #1, and 750 ± 400 lx in School #2. There was statistical difference between schools (p=0.046). Large variability was found in illumination within the same classroom (SD > 100 lx). This differences in illumination can be explained by the fact that School #1 had most of the blinds up and lights on, while in School#2 they were down and off.
Conclusions :
Modern tablets and smartphones can be used to decrease accommodation demand and to measure local classroom illuminance objectively, thus these devices can be used to alert the child or a remote guardian about a potential risk of myopia progression.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.