Screen Time Linked To Increased Risk Of Nearsightedness In Children, Study Finds
Authored by George Citroner via The Epoch Times (emphasis ours),
Even one hour of screen time per day significantly increases the risk of nearsightedness (myopia), especially for children, a new study suggests.
More Screen Time, More Risk
Researchers found that spending an additional hour per day (past the first) watching screens was associated with a 21 percent increase in the odds of someone developing nearsightedness.
The study analyzed data from 45 different studies involving more than 335,000 participants to find a complex relationship between screen time and nearsightedness risk. The analysis collected data from various digital devices such as smartphones, tablets, gaming consoles, computers, and television sets, which were collectively referred to as digital devices.
The findings of the systematic review and meta-analysis, recently published in JAMA Network Open, highlight a growing concern over children’s screen usage.
“As children increasingly embrace smart devices at younger ages and spend more time on digital screens, there is an urgent need to better understand the association of digital screen time with myopia,” the researchers wrote.
In the United States, estimates show nearsightedness prevalence to be about 42 percent. Among children specifically, as much as 41 percent of children in urban areas and 16 percent of children in rural areas are living with the condition.
The results suggest that daily screen time should be limited to less than one hour to potentially reduce the risk of developing nearsightedness.
Building on Previous Research
A previous meta-analysis combining data from 11 studies that included 934 participants looking at the relationship between screen time on smart devices (such as smartphones or tablets) and nearsightedness revealed a significant link—time spent on smart devices alone was associated with a 26 percent increase in the odds of developing nearsightedness.
When this screen time was combined with computer usage, the odds increased by 77 percent.
However, another meta-analysis that analyzed screen time data separately for different categories found that time spent on computers and televisions was linked to nearsightedness, but time spent on smartphones was not.
The researchers involved in the new study noted that findings such as these highlight a need for more in-depth investigations into the safety threshold for digital device exposure.
Why the Increased Risk?
Nearsightedness occurs when the eye elongates from front to back. This causes light entering the eye to focus in front of the retina rather than directly on it, which makes distant objects appear blurry, optometrist Dr. Meenal Agarwal, owner of Pickering Town Centre Optometric Clinic, Stouffville Family Eye Care, and Promenade Optometric Clinic, told The Epoch Times.
“It’s counterintuitive,” she said. “But the theory is that focusing on close objects for extended periods can put stress on the eye’s focusing system, which may influence the shape of the eye, causing it to elongate more than it would naturally.”
She said this applies when looking at anything closer than 22 inches to the face.
When staring at a screen, your eyes are constantly focused on a fixed distance, usually one very close to your face. This prevents the natural switching between focusing on near and far objects that happens in a natural environment. This means your eyes maintain a consistent focus for extended periods, straining the muscles responsible for changing your eye’s focus and potentially contributing to nearsightedness because of the prolonged near focusing effort required.
Agarwal said this increased stress may also prevent the eye from fully relaxing when focusing on distant objects, which could lead to changes in how the eye grows over time.
Reducing Myopia Risk
To reduce children’s risk of developing nearsightedness, Agarwal recommended encouraging kids to spend more time outdoors.
“Studies have found that children who spend more time outdoors tend to have a lower risk of developing myopia,” she said. “This is because exposure to natural light and focusing on objects at various distances, as we do outdoors, may help prevent myopia.”
Agarwal recommended approximately two hours of outdoor time per day for both children and adults to help prevent or delay the onset of nearsightedness. Reducing near work and taking breaks while doing near work are also very important, she said.
To help relieve the strain of prolonged near work, Agarwal advised following the “20-20-20 rule,” which means taking a 20-second break and looking at something 20 feet away every 20 minutes.
“Lastly, if your child is already myopic, consider myopia control options with your eye doctor like myopia control glasses, contact lenses, or treatments like atropine eye drops,” she said. “These have all been proven to slow the progression of myopia.”
