Children's eyesight is getting worse around the world, and there's a clear culprit to blame: increased screen time.
A new global study published in the British Journal of Ophthalmology found more children are experiencing nearsightedness, also known as myopia, in the last few years. Researchers said the change stems from kids spending more time in front of mobile devices, the TV and playing video games, particularly during the COVID-19 pandemic.
"These findings are an important step towards understanding the trends in myopia over time," the report said, "particularly in populations experiencing rapid transitions in myopia and the significant surge during the special period of the COVID-19 pandemic."
Although genetics can play a role in the development of myopia, it's also commonly caused by environmental influences like muscle strain. Myopia begins in early childhood and worsens with age.
The research, which analyzed studies of more than 5 million children from 50 countries across all six continents, found about one-third of children and teens across different demographic groups have trouble seeing things in the distance. Myopia is expected to exceed 740 million cases by 2050.
Beyond the pandemic, myopia has been on the rise for years, jumping from 24% to 36% of children in the last three decades. This number is expected to climb by an additional 9% in the next 25 years.
The US Centers for Disease Control and Prevention advises parents to limit kids' screen time and encourage them to play outdoors.
"Many children spend hours each day doing near-vision activities. Going outdoors allows them to look at distant objects. This lets their eyes recover from strain and fatigue," the agency says. "Playing outdoors also helps kids to be physically active and get essential vitamin D."
The countries with the highest numbers of myopia cases include Japan (86%), Korea (74%) and Russia (46%). These numbers also correlate to starting school at a younger age, consequently putting more strain on eyes to focus on school work. Kids in Asia, for example, can start as early as age 2. In Africa, children begin school between the ages of 6 and 8. Myopia is seven times less likely in Africa than in other regions.