YOSEMITE NATIONAL PARK, Calif. — For three days, my wife, Delaney, and I went off the grid. I didn’t see a single screen — aside to take the occasional photograph — read a single text message, send a single email, or watch one second of a video on social media. We had filled our packs with enough food and clothes for a 20-mile loop in Yosemite National Park, beginning on Thursday morning at the Rafferty Creek Trailhead, hitting Fletcher Lake by that evening, setting up camp at Lyell Canyon on Friday night, then taking a flat, 6-mile hike back to the car on Saturday.

When backpacking, everything about your routine is changed, rewound a few hundred years, at least. You rise and sleep with the sun, partly because your body wants to, partly because you sort of need to. We’d be in our tent by 8:30 at night — about 90 minutes before we usually fall asleep at our home in Hermosa Beach, Calif. — and wouldn’t get up until after 7, when the first early rays of light would begin peeking through our tent. We slept, on average, more than nine hours a night, once hitting 10, which is more than two hours above our normal.

It was, simply, amazing, for a number of reasons. We love time in nature. Crave it. Complex lives become whittled down to hiking, eating, setting up camp, and sleeping. That’s it. For three days, our phones were rendered obsolete. We didn’t attend a single meeting or Zoom. We didn’t scroll Instagram or TikTok.

There was no outside noise, just the rushing of the wind through a meadow, a bubbling creek, the roll call of Hyenas, the massive silence of the mountains. We lived as our ancestors did, and our bodies and minds thanked us for it, resetting our systems so that, even now, two days after returning to Hermosa and a world bathed in artificial light and noise, noise, noise, we’re still in bed by nine and not rising until seven. Much of this — almost all of it, really — is thanks to light.

We ran our lives how we were designed: With the rising and setting of the sun. It’s why we slept so well, why we felt fully charged despite eating minimally and living relatively dehydrated. Yet we cannot, of course, all live our lives full-time like this; not most of us, anyway. We have duties to which to attend: work to do, emails to answer, phone calls to make, messages to send. Our modern lives require an abundance of light, much of which is artificial.

For several months, I’ve been testing out BlueFree Optical glasses. They specialize in the study of blue light and understand the importance of natural light on our eyes throughout the day — from sunrise to sunset, they developed their lenses using a patented approach. We found each other after I wrote a blog post detailing the factors that were most highly correlated with enhanced recovery when I was wearing a WHOOP strap.

The No. 1 factor to my recovery, by a long shot? Blue light blockers. Wearing them consistently improved everything, especially both the quality, and quantity of my sleep, which is the closest thing an athlete has to a legal performance enhancing drug. It’s important to find glasses that actually block, not just filter, artificial blue light. I reached out to them for this piece on why spending so much time outdoors, away from artificial light, was so restorative in so many ways.

Take a walk

The forest, beach and waterfalls emit negative ions that are beneficial and naturally boost our serotonin, a chemical that carries messages between nerve cells in the brain and throughout your body. Negative Ions produce biochemical reactions that increase levels of the mood chemical serotonin, which helps to alleviate depression, relieve stress, and boost our daytime energy.

Bathe our eyes in sunlight at sunrise

This helps set your daily circadian rhythm; morning light has a lot of red and infrared light that acts as natural red light therapy. UVA on the skin also stimulates nitric oxide production, which brings blood to the surface of the skin so it can absorb more light throughout the day.

Wear BlueLight blockers when using a computer or phone for long periods

When I returned from Yosemite, one of the first things I did was make a quick vlog from the trip, which took roughly two hours. Then I watched football for another few hours. By noon, my eyes had the familiar tiredness from staring at a screen from 8-12. I didn’t need to feel this way, of course. It could have been prevented by simply wearing BlueLight Free Optical glasses, which block the blue lights emitted from our screens. Wearing the glasses would have two effects: My eyes wouldn’t be so tired, and my bodily systems wouldn’t be put off by the abundance of light, even during the daylight hours. Which brings me to my next point:

Wear the glasses after sunset whenever artificial light is present.

The main reason we were able to sleep so well in Yosemite at such early hours is not because we were so worn down from hiking, although that certainly played a part. It’s because of light. When the sun goes down, our bodies produce melatonin, a hormone produced by our brain which helps with the timing of our circadian rhythm. But when we continually use phones and computers and lamps and TV screens and produce artificial light, our brain isn’t quite so sure when to produce melatonin, or how much. It throws our sleep cycle into disarray. Aside from a headlamp used only to set up our tent, we had no artificial light in Yosemite, so when the sun went down, so did we, and our body responded in kind, allowing us to sleep hours earlier than normal.

It isn’t realistic to ask yourselves to use zero light after sunset, particularly with daylight savings approaching. To reduce the impact of using screens and artificial light, put on your blue light blockers as soon as the sun goes down, which will help your brain get the message that the sun’s down, and it’s time to produce some melatonin. It might feel funny to wear the glasses at such an early hour, but when you’re getting nine-plus hours of sleep per night and wake up feeling fully recharged in the morning, enjoying days exponentially more productive, you’ll be glad you did.

Wear the Yellow lenses while driving at night to reduce blue light and glare from vehicle headlights.

There were no cars in the high country of Yosemite. Just a handful of backpackers wandering around the John Muir Trail, and the occasional train of horses and donkeys. So we didn’t have to bother with the various lights that come with driving at night: headlights, the lights on our dashboard, the light from our phone displaying our map. It’s an easy fix to reduce the lights from cars and the gadgets within them: Put on your blue light blockers. We wear glasses during the day when we’re driving.

Why not wear them at night?

Keep blue light blockers by your bed

As best we can, we want to stay off our phones and devices at bedtime, and especially in bed, but our phones are just such useful tools, and most of us use them for our alarm clocks. But even a momentary blast of blue light from a screen can put a pause on melatonin production and disrupt your sleep for hours to come. So keep a pair of blue light blockers by your bed for when you have to set your alarm, send any last-second messages, or do any reading, if you use your phone for that.

Your mind, body, and sleep will thank you.

This post originally appeared on the Sandcast Blog, the most popular podcast for players, by players.