Of course, no one should never, ever look at the sun since that can cause permanent vision loss and blind spots. That being said, children need a certain amount of daylight in order for the eyes to develop properly. We are not unsure how much light intensity, what wavelengths are important or how much each individual person needs. What is known is that no artificial light is able to match what the sun provides naturally. Another consideration is that many of us are living in latitudes and environments that our ancestors had much longer to adapt to. The propensity for nearsightedness or myopia certainly has genetic risk factors that we have not fully identified. Regardless, childhood myopia continues to grow at an alarming rate. "There are approximately 30 million children in the U.S. today [in 2022] with some level of progressive myopia, and another 1 million join them every year," according to Dr. Richard Lindstrom. There are multiple reasons for this increase but the increasing near demands on kids during the critical developmental years plays an important factor. Many kids may spend over 12 hours a day focused up close on not just screens but books and papers as well. And since myopia affects 40% of Americans and growing, what we have been doing right now is not sustainable.
Being highly myopic is not just inconvenient in needing to wear glasses and contacts. Having a more elongated eye significantly increases the risk of eye diseases later in life. The greater the number or degree of myopia, the greater then risk of disease. So "Every diopter in progressive myopia matters."
Being aware of how much time we are spending outside helps provide useful personalized information to guide our daily habits. Just like logging water intake, having an idea of how much sunlight we are getting now can help us track and build more sustainable health habits. As of Apple iOS 17, the Apple Watch as well as iPhone can track "Time in Daylight." Research suggests we need at least 2 hours of daytime outdoor light per day but when, how long, and what kind of light is something that we do not presently know. The frustrating thing is we still know so little about how much each individual child needs at which age and each stage of development. So for some kids, that needed number for time outside could be 1 hour of morning sun between 8-9 am and 1 hours of afternoon sun between 3-4 pm in the winter but perhaps only 20 minutes of each session in the summer (and perhaps at different times in the summer). There is still so much we do not know though we are learning more all the time. For now the general guidelines for slowing myopia as shown below are useful as the foundation of treating myopia.
Spend at least 2 hours per day outside
Spend less time on screens
Keep your distance
The American Academy of Ophthalmology's EyeSmart initiative provided the infographics in this post. To find out more, please visit the nearsightedness page on the EyeSmart website.