How Screen Time Affects Children's Vision: Myopia, Prevention, and Outdoor Time

If there’s one thing we can all agree on, it’s that kids love their iPads. But with more children needing glasses every year, it’s hard not to wonder if all that screen time is the reason why their vision is getting worse. So, how exactly does screen time affect vision, and how much is too much? Let’s dive into this topic in today’s episode of "Antonio the Optometrist."

The Connection Between Screen Time and Vision

When kids come in for eye tests, and we find that their vision has worsened, parents often ask me to remind them about spending too much time on their devices and listening to their parents more. While it’s true that screens can contribute to worsening vision, it's not the whole story. To understand this better, we need to first look at what myopia (nearsightedness) actually is.

What Is Myopia?

Myopia is a condition where the eyeball grows longer than normal, causing distant objects—like a school whiteboard—to appear blurry, while things up close, like a book or a tablet, remain clear. This is why it's called nearsightedness. Glasses are often needed to see things clearly, and as myopia progresses, stronger prescriptions are required. Myopia usually worsens until about the mid-20s, at which point it often stabilizes. If left unchecked, severe myopia can lead to complications, so it’s important to understand how to prevent it.

Why Does Myopia Happen?

Myopia is multifactorial, meaning there are several contributing factors, but the main ones are:

1. Genetics
2. The amount of time spent doing near work (like screen time)
3. The amount of time spent outdoors

Let’s break down each factor to see how they fit together.

The Role of Genetics

Think of your eye’s growth as a recipe handed down by your parents. Your genes are the ingredients, and they play a significant role in whether or not you develop myopia. Studies have identified over 400 genes linked to myopia, highlighting its complex genetic structure. If one parent is myopic, you’re about 1.5 times more likely to be nearsighted. If both parents are, your odds increase to about three times.

It’s similar to height: if your parents are tall, you’re likely to be tall too, but not everyone will have the same height. Likewise, with myopia, having myopic parents increases your risk, but the severity can vary.

Although we can’t change our genes, it’s crucial to understand that myopic parents might have habits that contribute to myopia. For instance, people with higher education levels tend to be more myopic, and they might encourage their children to study more, indirectly increasing the risk of myopia.

The Impact of Near Work

During school years, kids spend a lot of time doing near work—whether it’s reading books, using laptops, or playing on iPads. There’s enough evidence to suggest that more near work leads to more myopia, although the exact reasons aren’t fully understood. Some studies even suggest that screen time doesn’t significantly impact myopia progression, but it seems logical to assume that reducing screen time could help slow down worsening vision.

While the scientific community is still debating how much screen time is too much, the general consensus is that less is better, especially for children. The World Health Organization (WHO) offers some guidelines:

• Under 1 year: No screen time. Instead, focus on reading and storytelling with a caregiver.
• 1-2 years: Still no screen time recommended.
• 2-4 years: Limit screen time to no more than 1 hour per day, with less being better.
• 5-17 years: No more than 2 hours per day.

Once vision stabilizes—meaning your optometrist says it’s no longer worsening—the amount of screen time becomes less of a concern. However, until that point, reducing screen time is a safe bet.

The Benefits of Outdoor Time

Spending time outdoors has been shown to be one of the most effective ways to prevent myopia. A 2017 meta-analysis found that children who spent an average of 10 hours a week outdoors had about half the risk of developing myopia. Even for children who are already nearsighted, increasing outdoor time can slow down how quickly myopia worsens.

For example, in 2010, the Taiwanese government introduced the 10-10-120 program, encouraging children to spend at least 2 hours outside every day. Since its introduction, the rate of myopia progression among school children has significantly dropped.

Similarly, a 2019 study from the Netherlands showed that children who spent more time outdoors and less time on near work had a significantly lower risk of developing myopia. So, the general advice is to reduce near work and increase outdoor time to minimize myopia progression.

Final Thoughts

For parents worried about their children’s screen time, the best solution might be to encourage more outdoor activities. When kids are outside, they’re naturally doing less near work, which can help slow down myopia progression. Although studies suggest that screen time might not be the main cause of worsening eyesight, reducing it is certainly a safe option.

If you’re looking for more ways to control myopia beyond reducing screen time and increasing outdoor activities, stay tuned for my upcoming video on myopia control methods, which have shown promising results.

In Summary:

Yes, screen time isn’t great for your eyes, but rather than just cutting back on device use, it’s more effective to go outside and enjoy the sunlight. Indoor light exposure simply doesn’t compare to what you get outdoors, even on a cloudy day. So grab your sunglasses, slap on some sunscreen, and get some fresh air!