If you’re struggling to fall asleep at night, the fix might lie in something you did—or didn’t do—14 hours earlier. We tend to think of sleep as something we “turn on” at bedtime, with warm tea, eye masks, or calming music. But sleep isn’t a switch. It’s a rhythm, and that rhythm starts ticking the moment you wake up. According to a neuro-specialist, if there’s one thing you should perfect in your life to support brain health, it’s your sleep—and the way to do that doesn’t start at night. It starts with sunlight.

In this post, we’re diving into the most underrated—and counterintuitive—sleep strategy out there: early morning sunlight exposure. Yes, the best thing you can do to fall asleep at night is to step outside shortly after you wake up. Here’s why.

Understanding Your Circadian Rhythm — Your Body’s Sleep Clock

Your circadian rhythm is your body’s internal clock. It runs on a 24-hour cycle and regulates everything from when you feel alert to when your body naturally starts winding down. It’s not just about sleep—it impacts your energy levels, focus, and even hormone balance throughout the day. But here’s what most people get wrong: your circadian rhythm is heavily influenced by light. Not just any light, but natural sunlight, especially in the morning. It’s one of the most powerful signals your brain uses to determine when to stay awake and when to produce melatonin—the hormone that helps you fall and stay asleep. The problem? Most people wake up and reach for their phones. They scroll for news or dive into email before ever stepping outside. Many don’t see natural daylight until hours later—or not at all. This seemingly harmless habit throws your internal clock off course, making it harder to fall asleep when you actually want to.

Morning Sunlight — The Natural Trigger for Nighttime Melatonin

Here’s the part that surprises almost everyone: exposing your eyes to sunlight in the morning helps your brain produce melatonin later at night. This happens because early light exposure sets off a chain reaction in the brain. Your body begins a countdown from that moment—about 12 to 14 hours later, melatonin production kicks in, making you feel naturally sleepy. But there’s a catch. It’s not enough to just be outside. You need sunlight in your eyes—without sunglasses—within an hour of waking. This doesn’t mean staring at the sun (don’t do that), but rather letting daylight reach your eyes directly. Wearing sunglasses first thing in the morning blocks the light’s full effect and reduces the brain’s ability to calibrate your clock. It only takes 5 to 10 minutes. Drink your coffee on the patio. Go for a short walk. Step onto your balcony. It’s simple, free, and incredibly effective—and yet most people skip it entirely.

The Power of Light at Both Ends of the Day

Your circadian rhythm doesn’t just need a morning signal—it also benefits from a natural off switch. That’s where dusk light comes in. Evening light—especially the softer, reddish tones of dusk—helps reinforce the message to your body that the day is ending. It tells your brain to wind down and start prepping for rest. Just like the morning, spending a few minutes outside around sunset gives your body the cues it needs to close the loop. Think of it as “circadian bookending”: a bit of light in the morning to start the rhythm, and a bit in the evening to bring it to a close. Neither requires a major lifestyle shift. Just stepping outside—ideally without sunglasses—for 5 minutes at each end of the day can have profound effects on your ability to sleep deeply and wake up refreshed.

The Silent Saboteur — How Blue Light Disrupts It All

There’s another light signal that’s working against you—and you’re probably surrounded by it every night: blue light from screens. Phones, TVs, tablets, and computers all emit blue light. And while all light can affect sleep, blue light is especially disruptive because it closely mimics sunlight. When your brain sees blue light in the evening, it gets confused. It thinks it’s still daytime. As a result, melatonin production is suppressed and your ability to wind down is delayed. That’s why scrolling through your phone at 11 PM can leave you feeling wired, even if you were tired an hour earlier.

In a perfect world, you’d avoid screens for two hours before bed. But if that’s not realistic, there’s a middle ground: blue light blocking glasses. Wearing these in the evening can reduce the disruptive effects of screens and help your brain transition into nighttime mode, even if you’re catching up on emails or watching your favorite show.

Small Habits That Can Transform Your Sleep

Let’s turn insight into action. Here are a few simple, science-backed steps you can take today to start resetting your circadian rhythm:

  • Get outside within an hour of waking. Aim for 5–10 minutes of sunlight, without sunglasses.
  • Repeat the exposure at dusk. Just 5 minutes outside during sunset can reinforce your sleep rhythm.
  • Avoid screens two hours before bed, or wear blue light blocking glasses if you can’t.
  • Keep lights dim in the evening, especially overhead lights that mimic midday sun.

These aren’t life overhauls—they’re minor adjustments. But your body is designed to respond to natural light cues, and giving it those signals can have a massive impact over time.

Rethinking Sleep Starts With the Sun

If you’ve been struggling with sleep, maybe the problem isn’t your mattress, your supplements, or your nighttime routine. Maybe the real issue is that you’re missing the morning signal your brain needs to stay on rhythm. Sleep is a full-day strategy, and the most powerful way to start is also the simplest: step outside and let the sun hit your eyes. Try it for a week. Commit to five minutes in the morning, and five at dusk. You might be surprised at how quickly your body—and your sleep—starts to shift.