Can Excess Screen Time Harm Brain Health in Adults?
If you’re looking to safeguard your brain health, it helps to know that it can be impacted by a number of things. That includes your eyesight.
Previously, we reported that uncorrected vision can potentially increase your risk of experiencing cognitive decline. That means you can significantly reduce your likelihood of developing conditions like dementia if you proactively care for your eyesight. You can do so by getting regular eye exams, wearing prescription glasses or contact lenses, or undergoing necessary procedures like cataract surgery.
However, that’s not the only way you can be affected by the relationship between your eyes and brain. Today, researchers confirm that excess screen time can significantly harm brain health—not just in children, but in adults, too. With the average American spending more than seven hours a day looking at screens for work, leisure, and everything in between, this may be something you want to look into.
Excess screen time and the adult brain
Screen time initially affects the eyes, which in turn impacts the brain. That’s because excess time spent looking at digital displays keeps the eye muscles in one position for longer, causing fatigue. At the same time, the blue light they emit exposes your eyes to more glare, significantly reducing your blink rate and preventing your eyes from naturally moisturizing and refreshing themselves. The resulting dehydration blurs your vision, causing your eyes to work harder just to see clearly—and making it more challenging for your brain to decipher the images they send over. Researchers postulate that this is due to cognitive load theory. Because excess digital device use reduces blink rate and increases the number of incomplete blinks, it can potentially worsen cognitive load, lower your working memory, and ultimately reduce your ability to comprehend, retain, and learn new information.
When excess screen time becomes a habit, it can thus significantly impact brain health. In adults aged 18 to 25 years old, researchers have observed a more pronounced thinning of the cerebral cortex, the part of the brain that’s responsible for memory processing, decision-making, and problem-solving. Individuals who watch TV for five hours or more a day have a higher risk of developing both Parkinson’s and dementia. More concerningly, adults officially diagnosed with a smartphone addiction are more likely to have a lower volume of gray matter. This determines not just the robustness of your cognitive abilities, but also how you move and the emotions you feel—which is why our guide to brain plasticity notes that it plays a significant role in forming an individual’s unique abilities. Gray matter naturally decreases as you get older, meaning that excess screen time can accelerate how fast the brain ages.
As such, it’s crucial to be mindful of both how much time you spend looking at screens and how you treat your eyes in the process. Taking the following steps can help you keep your brain healthier in the long term.
Screen time solutions for better cognitive health
Protect your eyes
Your eyes are directly connected with your brain, which is why protecting them from digital eye strain can be especially helpful for safeguarding your cognitive health. That’s especially true since digital device use is now necessary for multiple aspects of our day-to-day routines, including working, studying, communicating, and more. To prevent eye muscle fatigue, many eye care professionals recommend the 20-20-20 rule: every 20 minutes, look at something 20 feet away for 20 seconds. For unavoidable periods of prolonged screen time, such as when working toward a deadline, you can shield the eyes from excess glare by wearing blue light glasses. Available both with and without a prescription, these use filters that can effectively prevent blue light overexposure. At the minimum, that can improve visual comfort by mitigating how much blue light reduces your blink rate. For them to be truly effective, however, even non-prescription blue light glasses need to account for your pupillary distance. If they’re not designed around the distance between the centers of your pupils, they can worsen eye strain instead of resolving it. You can figure out how to measure pupillary distance with the Opthy app. It can take your measurements automatically using your smartphone camera, so you can get the necessary blue light glasses as soon as possible. Finally, you can supplement your eyes’ natural moisture with artificial tears. Eye drops with oil-based formulas are generally considered the most effective for achieving long-lasting hydration, which can help you further protect your eyes from the dryness that can exacerbate eye strain—and worsen cognitive loads.
Limit screen time
Minimizing recreational device use can directly reduce how excess screen time affects your eyes and brain. To reap additional benefits, it’ll be most effective to do so before bed and immediately after you wake up. You can start by restricting device use in the bedroom, especially before you sleep. Since blue light mimics sunlight, late-night screen time can keep you alert and promote sleep deprivation. In turn, a lack of sleep can damage the hippocampus—which is responsible for learning and memory—and increase your risk of developing Alzheimer’s. Finally, you’ll want to refrain from scrolling on your phone after your morning alarm. Exposing your half-awake brain to the likes of emails and social media can stimulate it, triggering a fight-or-flight response that puts it in a state of anxious hypervigilance for the rest of the day. By refraining from device use for at least an hour after you wake up, you can better manage your stress levels so they don’t exacerbate the damage your brain incurs from excess screen time. However, arguably the most important thing you can do is track your screen time. That way, you become more aware of how much time you actually spend on device use and can spot areas in your routine where you can cut down. The StayFree app can guide you through how to conduct screen time audits. It’ll determine what activities you use your devices for most frequently. That way, you can more intentionally leverage screen time, reduce instances of unconscious content consumption through methods like doomscrolling, and keep yourself accountable in the process.
