Does Staring at Screens All Day Really Hurt Your Eyes? Here's What You Need to Know

A question I hear all the time—from both patients and viewers—is whether staring at screens all day can really hurt your eyes. The answer isn’t as straightforward as you might think. It’s both yes and no, depending on a variety of factors. In today's video, we’re going to dive deep into what science says about the impact of screens—whether they’re from computers, phones, tablets, or other digital devices—on our eyes. Let's unpack this together.

Will Staring at Screens Make My Eyesight Worse?

One of the most common concerns people have is whether staring at digital screens—like those on your laptop, desktop, or phone—can cause their eyesight to deteriorate over time. Specifically, many worry that their glasses prescription will get stronger and stronger each year because of screen time. Scientifically speaking, the answer to this is a bit nuanced: it’s a “maybe,” with a slight lean towards “probably, yes.”

The idea that prolonged focus on near objects can lead to worsening eyesight, particularly increasing nearsightedness (or myopia), isn’t a new concept. In fact, it’s been around for centuries. For example, a friend of mine who practices family medicine has an old medical book from the 1800s that warns about this very issue—indicating that even back then, experts were cautious about the potential effects of near work on vision.

We’ve long observed that individuals who pursue higher levels of education, which often involves extensive reading and close-up work, are at a greater risk of developing myopia. This correlation has been noted in many studies over the years. More recently, a meta-analysis—a study that combines results from multiple studies—confirmed that myopia progression is likely associated with near work, which includes activities such as staring at computer screens, tablets, and phones. However, it’s not just screen time; simply being indoors is also considered a significant risk factor for developing myopia.

When it comes to screens specifically causing nearsightedness to worsen, the data isn’t entirely conclusive. What we do know is that engaging in near activities, in general, increases the likelihood of needing stronger glasses over time. So, whether you’re reading a book or staring at your computer, the risk is there.

Some studies suggest that the progression of myopia is associated with the number of hours spent on continuous near work. For example, think about the 8 hours you might spend at your computer for work, followed by another 6 to 8 hours using your phone or tablet. Does that sound familiar? It’s the combination of these prolonged periods of near focus that might be contributing to worsening vision. Additionally, holding screens very close to your face may further increase this risk, which is particularly concerning because most of us tend to hold our phones quite close.

Interestingly, at least one study found that taking a break after 30 minutes of continuous reading, combined with spending at least 2 hours outdoors, can slow the progression of myopia in university students. This suggests that integrating regular breaks and outdoor activities into your routine may help mitigate some of the risks associated with long hours of screen time.

In summary, it might not be the screens themselves causing your eyesight to worsen. It’s more likely due to the cumulative effect of all the near work you’re doing throughout the day. But screens certainly play a role in this, given how much time we spend on them.

Will Staring at a Computer Screen Damage My Eyes?

Another major concern I often hear is whether staring at a computer screen can cause physical damage to the eyes—like burning a hole in the retina or leading to blindness. This kind of fear is often related to the infamous “blue light” that screens emit.

There’s a lot of ongoing research about blue light, and while there are valid concerns regarding its impact on our eyes, brain, and overall health, we don’t have all the answers yet. The idea that blue light could cause damage to the eyes and contribute to conditions like macular degeneration makes some sense, particularly when you consider the blue light we’re exposed to from the sun. The sun is the primary source of blue light and emits far more energy than any digital device.

Because of the sun's sheer power, it’s understandable why there’s concern about blue light. Some studies suggest that people who are exposed to more sunlight may have a higher risk of developing certain eye conditions. However, this evidence is still debated within the eye care community. When you compare sunlight to the blue light emitted by your computer screen, it’s like comparing a bonfire to a candle—the sun’s energy output is exponentially greater.

In laboratory settings, animal studies have shown that exposure to blue light from artificial sources can damage photoreceptor cells in the eyes, primarily through oxidative damage. However, it’s important to note that these studies were conducted on lab animals or on retinal cells in a petri dish, not on living human eyes.

The human eye is equipped with numerous support structures designed to prevent oxidative damage and maintain overall eye health. Therefore, the research community is still awaiting more conclusive evidence regarding the potential harm blue light from screens might cause. As of now, the risk seems relatively low, especially considering the lower energy output from screens compared to the sun.

One aspect of blue light that we do understand better is its effect on our circadian rhythm, which is our body's internal clock that regulates sleep and wake cycles. Certain retinal cells are more sensitive to blue light and play a crucial role in managing our sleep cycle, mood, and even metabolism. So, while it’s doubtful that blue light from your screen will cause direct retinal damage, staying up late at night staring at your phone could certainly disrupt your sleep quality and overall well-being.

How Digital Screens Impact Your Eyes: Dry Eyes and Eye Strain

Now, let’s explore two ways that digital screens are known to affect our eyes: dry eyes and eye strain. Together, these symptoms are often referred to as Computer Vision Syndrome (CVS).

Dry Eyes: One of the primary ways digital screens contribute to dry eyes is through tear film evaporation. Research shows that when we focus on a screen, our blink rate decreases significantly—by about two to three times—compared to when we’re engaging in a normal conversation or other activities that don’t require such intense visual focus. When your blink rate drops, your eyes don’t get the moisture they need from blinking, which can lead to dry, irritated, and red eyes.

Additionally, research has found that when we do blink while using screens, our blinks often aren’t complete. In other words, your eyelids may not fully close, which leaves a portion of your eye exposed to the air. This can cause the tear film—the protective layer of moisture on the surface of your eye—to evaporate more quickly, leading to that uncomfortable dry eye sensation.

Interestingly, tasks that require a high level of concentration, like reading or typing, are more likely to reduce blink rates and cause dry eyes compared to activities like watching a movie, which may not demand as much visual focus. Therefore, learning to relax your gaze and taking regular breaks can help maintain a healthier blink rate and reduce dry eye symptoms.

Eye Strain: Eye strain is a bit more complex, as it involves several different eye muscles working together. These muscles are responsible for focusing on close-up objects, aligning your eyes properly, and adjusting the size of your pupils to ensure clear vision. When you spend long periods staring at a screen, these muscles can become overworked, leading to eye strain, fatigue, and discomfort.

Your eye muscles are connected neurologically, meaning that if one muscle is working harder, the others have to adjust to maintain balance. When you introduce a pair of prescription glasses into the equation, it can complicate things even further. This complexity is why there are entire professions, like optometry and vision therapy, dedicated to understanding and treating how these muscles work together.

Although there isn’t a lot of research specifically on the effects of screens on this entire muscle system, we do know that prolonged use of screens can reduce your eye’s ability to focus accurately on close objects. This reduced focus can contribute to discomfort and eye strain, particularly if you’re using screens for extended periods.

When your eyes are trying to focus on something close up—like your phone screen—they’re not always focusing exactly at the plane of the screen. Instead, there’s a small amount of lag, meaning your eyes naturally want to focus slightly behind the object. If you have difficulty maintaining focus, your extraocular muscles (the muscles on the outside of your eyes) may kick in to help, which can further strain your eyes.

For some people, this constant effort to keep things in focus can lead to symptoms like double vision or seeing shadows behind letters when reading. These symptoms are often a sign that the muscles in your eyes are struggling to work together efficiently.

Conclusion: What We Know About Screens and Eye Health

In conclusion, it’s safe to say that digital screens can contribute to eye strain, dry eyes, and potentially disrupt your sleep cycle due to blue light exposure. For those who spend a lot of time on screens, especially doing near work, there’s also a higher risk of worsening nearsightedness. However, it’s important to note that it’s not just the screens—it’s the overall amount of near work and lack of breaks that matter.

So, what about you? Have you noticed any changes in your eyes from using digital screens? Are your eyes feeling dry, tired, or fatigued? Has your glasses prescription changed recently? I’d love to hear your experiences, so please share them in the comments.

If you’re dealing with eye strain from screen time, I’ve made several videos offering tips that have helped me reduce eye fatigue and discomfort. You can check them out by clicking on the screen.