The 20-20-20-20 Rule

By Shivani Tripathi

By now, we all know the drill: wake up, sit at your desk, and open your laptop to watch lectures. Stare at your screen until it’s time to get lunch and then get back on your computer to attend more classes and office hours. Afterwards, read online textbooks to do homework. Click on a Zoom link to join club meetings. When the day ends, watch an episode of Netflix, scroll through social media, and record Tik Toks. Try to fall asleep, with a dull headache and strained eyes.

As the coronavirus pandemic has put college students at the complete mercy of technology, many medical professionals recommend the 20-20-20 rule to deter digital eye strain. However, the rule does not account for another dangerous consequence of digital dependence: sedentarism. Online school has forced otherwise healthy and active individuals into sedentary lifestyles, increasing the risk of life-threatening illnesses such as cancer. To prevent both digital eye strain and the potency of sedentariness, it is integral that we add a fourth 20 to the 20-20-20 rule.

The first three “20s” of the rule address digital eye strain. The rule advises that for every 20 minutes spent staring at a screen, you look away for 20 seconds at a spot at least 20 feet away. Digital eye strain is a direct consequence of excess screen time. Symptoms include ocular and general fatigue, double vision, blurred vision, red eyes, and ocular burning sensations. These painful sensations occur because prolonged screen time overworks the ciliary muscles in our eyes. The ciliary muscle determines the shape of our lens and our ability to focus. By staring closely at a screen for too long, we deprive our ciliary muscle of the periodic rest it needs. The ciliary muscle remains contracted, causing our eyes to feel strained and sore. 

Furthermore, studies have shown that digital eye strain could lead to dry eye disease. Prolonged  screen time leads to reduced blink rates. While people normally blink approximately fifteen times per minute, computer use can decrease this rate to as low as five. Blinking hydrates the cornea, spreading tears and nutrients across the surface of the eye. Incomplete blinking leads to the evaporation of tears, and ultimately dry eye disease. 

To mitigate digital eye strain, students are invited to consider following the 20-20-20 rule. Abiding by the rule relaxes the eye muscles, giving the ciliary muscle some rest. Think about it this way: all muscles in our body need breaks if overworked. For example, weightlifters have scheduled rest days during the week to let their muscles repair and heal.

Beyond the eyes, excessive computer use wreaks havoc on the rest of your body as well. In fact, research indicates that people who sit for more than six hours a day die earlier than people who sit for three hours or less. To counter such ramifications, it is vital to add a fourth 20 to the 20-20-20 rule: A 20 second walk. Every 20 minutes, college students should get off their laptops and walk for 20 seconds. This can be accomplished by grabbing water, or you could just walk back and forth in your room a couple of times. 

Taking quick, routine walks throughout the day is essential to avoid the life-threatening consequences of sedentariness. Even if you exercise daily, an hour of concentrated physical activity won’t undo the harm of four hours of straight sitting. A study published in the Journal of National Cancer Institute reports that prolonged periods of sitting increases the risk of cancer. With every two-hour increase in sitting time per day, the chances of getting colon, endometrial, and lung cancer increases by 8 percent, 10 percent, and 6 percent, respectively. Researchers noted that the higher risk “seemed to be independent of physical activity, suggesting that large amounts of time spent sitting can still be detrimental to those who are otherwise physically active.”

Another consequence of sedentariness is a bad posture. Hunching your back and slouching while scrolling on your laptop can ruin your posture. A poor posture results in back, neck, and shoulder pain. Moreover, bad posture negatively impacts the amount of air entering your lungs. Impaired lungs lead to lower oxygenation in the heart, brain, and other vital organs. Other repercussions include poor circulation, heartburn, and poor digestion. Fortunately, taking short, 20 second walks can correct your posture throughout the day. 

Hopefully, a coronavirus vaccine will soon become available and we can all return to normalcy. However, the pandemic didn’t create digital dependence—it exacerbated it. Even if the coronavirus is eradicated, screens, sedentary behavior, and the health risks they pose will persist. For a digital generation, the 20-20-20-20 rule could be a lifelong tool with which we can use technology in a healthy manner.