New study says kids need outdoor light to improve their vision
As if there aren’t enough reasons to turn off the screens and get your kids outside, here is another big one. We now have proof, from a big study done in China, a study that spanned over a few years, that being outside and being away from close-up work like reading and looking at screens significantly reduces a child‘s chances of developing nearsightedness, a condition also called myopia. I guess the Chinese are particularly interested in myopia since they have such high incidence of myopia. Among urban older Chinese, the rate of nearsightedness is currently 90%. I guess that is why they invented glasses– a very strong need. So it is fitting that the Chinese were the ones who proved that spending at least 40 minutes outside on a daily basis, greatly reduces a child‘s chance of becoming myopic.
Ophthalmologists have suspected for years that doing a lot of up close work like that done in school encourages the development of myopia. Now we have proof that spending more time outdoors, in natural light, looking off in the distance reduces a child’s chance of needing glasses. To me, this only makes sense but let’s break this down a little more with a trip down science lane.
A child’s eyes have a lot in common with a camera– both have light bending structures that focus incoming images. In the case of your child, this would be their corneas and lens in the front of their eyes. Their eyes also have an aperture to adjust the amount of light entering the eye–the iris of the eye, and a “film equivalent” that senses the light and records the images– the child’s retina. For everything to work correctly, the images coming in from the cornea, lens, and aperture have to focus exactly on the retina for the image to be clear. If the child’s eyeball is too long and the visual image focuses in front of their retina, that is called nearsightedness or myopia–time for some spectacles. If their eyeball is too short or the cornea and lens can’t bend the light to focus on the retina, that is called farsightedness but by far, the most common visual disturbance in children is nearsightedness or myopia. The recent studies that that you can find in the Smo Notes of this pedcast, seem to indicate that a child’s eye is meant to develop the proper length and focusing power when they spend a good amount of time each day (at least 40 minutes) looking out into the distance, outdoors, in natural sunlight. These factors somehow bring all the optical forces into balance and allow the child to develop good near and distance vision.
Current recommendations to help your child’s vision:
While we are talking about vision, let me take a minute to remind you of some good habits to get into when they are young and you are responsible for their visual development:
Encourage your children to wear polarized sunglasses as much as possible when they are outside in strong UV light–the 10:00am to 2:00pm period of time. Doing so may prevent them from developing cataracts as they age into adulthood.
Make sure that as your kids get older and are around heavy equipment like lawnmowers, farm equipment, and sporting events where objects are flying at high speeds, that they wear protective eyewear. Damaging or losing an eye is a devastating and usually preventable event in childhood.
As recent evidence has shown, spending at least 40 minutes outside each day focusing on objects in the distance can improve your child’s vision and reduce their chance of nearsightedness and the need for glasses.
Make sure your children have diets rich in the nutrients that their eyes need for proper function- green leafy vegetables, eggs, nuts, citric fruit, and omega fats that are found in fish. (a more complete list found in the Smo Notes)
And finally, some experts believe that a child should sleep in complete darkness, with no artificial lights in their bedroom. By the way, this recommendation also includes TV’s and other screens devices. I think your children’s rooms should be as dark as possible.
And let’s not forget Grandma’s wisdom about sitting too close to the TV. She knew the same thing. That must have been why she was always insisting that her kids turn off the TV and go outside and play. Once again, Grandma runs out to be a genius and ahead of her time. Amazing.
Thanks for joining me today for this installment of Portable Practical Pediatrics. If you enjoy learning about kids in this format, be sure to subscribe at my website, www.docsmo.com and consider writing a review on iTunes and feel free to share these posts with friends and relatives. This is Doc Smo, recording in studio 1E, that’s my first child’s bedroom on the east side of my house, hoping that when it comes to your child’s eyesight, you get it right. Until next time.
Outdoor activity decreases incidence of myopia-Chinese study
Incidence of Myopia in East Asia versus other populations.
Screens, close-up work, and lack of sunlight increase myopia.
Lack of Sunlight associated with myopia
Reading on your back reduces myopia.
Nutrients that children need for good vision
Does sleeping in a room with light cause myopia?