A Japanese government survey shows that nearsightedness is starting to occur at an early age, affecting 6th-graders at the same level as adults.
The Education Ministry survey in fiscal 2021 covered about 8,600 elementary and junior high school students.
The national survey of children was the first to examine the length of the eyeball axis, between the cornea and retina, as a measure of nearsightedness.
Nearsightedness often occurs as the axis gets longer, causing visual information entering the cornea to be focused before reaching the retina, which detects brightness, colors and shapes.
The average axis length among adults is around 24 millimeters. In the survey, the average among sixth-grade boys was 24.22 millimeters, and among girls 23.75 millimeters.
The figure was even higher among students in their third year of junior high school, at 24.61 millimeters for boys and 24.18 millimeters for girls.
The survey also shows that about 20 percent of first-graders in elementary school had eyesight below 1.0, or average vision. The percentage grew to around 60 percent among third-year junior high students.
Professor Ono Kyoko of Tokyo Medical and Dental University led the survey. Ono expressed concern about the trend, saying children's axes could get even longer as they grow.
The professor plans to analyze the data further to see whether children's increased use of smartphones and tablets for remote learning during the pandemic might have affected their eyesight.