120
Participants
Start Date
April 10, 2023
Primary Completion Date
May 15, 2023
Study Completion Date
May 15, 2023
red light and distant image screen
red light plus distant image screen, children use these two devices at the same time
red light
children use red light for 3 minutes each time, twice a day
distant image screen
Children in this group were asked to use this device for ≥1 hour/day
Beijing Tongren Hospital, Beijing
Beijing Tongren Hospital
OTHER