Light does more for us than just helping us see. It plays a super important role in keeping our body in sync with the day.
The light we’re exposed to influences when we wake up, when we sleep, how we focus, and even when we go to the bathroom.
Let’s take a closer look at how light guides many of our body’s daily functions and why the timing of our exposure to light is important.
What Is the Body Clock?
Our body has an internal system that runs on a 24-hour cycle, which is called the circadian clock, or body clock. This system controls when we feel tired, awake, or alert during the day.
It also influences how our organs work.
The body clock is managed by signals sent through the nervous system and hormones, helping our body stay on track with the daily cycle of light and dark.
Interestingly, our body has more than one clock. There’s a central clock in the brain, and every organ has its own clock too.
These clocks all work together to keep us functioning properly. The central clock is located in the hypothalamus, a part of the brain that controls things like temperature and appetite.
This clock is mainly controlled by the light our eyes take in, which is why sunlight in the morning helps wake us up and set our day in motion.
How Does Light Help You Sleep?
One of the most important ways light affects us is by telling our body when it’s time to sleep. A hormone called melatonin is the key player here.
When it gets dark, our body starts producing melatonin, making us feel sleepy. On the flip side, when it’s light outside, melatonin production stops, helping us feel more awake.
Your sleep schedule can also be influenced by your “chronotype,” which is determined by your genes. Some people are naturally early risers, or “larks,” while others are “night owls” who stay up late.
But regardless of your chronotype, too much light at night—like the glow from streetlights or screens—can disturb your sleep and even harm your health.
Exposure to light at the wrong time can mess up your body clock, leading to problems like poor heart health, depression, and even a higher risk of serious conditions like diabetes.
Night-shift workers often struggle with these issues because their body clocks are out of sync with their work hours.
This can lead to health risks, as their bodies aren’t receiving the right signals from light to regulate their daily functions properly.
Light and Digestion
Even your gut follows a daily rhythm that is influenced by light. Your digestive system works harder during the day when you’re more active and slows down at night when you’re resting.
The muscles in your intestines that move food and waste are more active during the day and less active at night.
The peak time for bowel movements often happens in the morning, starting around 6:30 a.m. That’s why many people feel the urge to go to the bathroom early in the day.
This rhythm is controlled by the clocks in your digestive organs, along with the central clock in your brain, which all work together to keep your body running smoothly.
How Light Affects Your Focus
Light doesn’t just impact your sleep and digestion—it also plays a role in how well you can focus. Our body clock affects our brain’s ability to pay attention and stay alert at different times of the day.
Most people feel more focused and alert in the afternoon and evening, while attention tends to dip during the early morning and late at night.
This pattern explains why some people might find it harder to concentrate in the morning, and it can also affect things like productivity and even road safety.
For example, when daylight saving time starts and we suddenly lose an hour of sleep, our body clocks struggle to adjust.
This can make people feel more tired and less focused, especially in the morning, which leads to a higher risk of car accidents during that time.
Other Ways Light Affects Your Body
Your body clock does a lot more than just regulate your sleep, digestion, and focus. It also affects other important functions:
- Physical performance: The body clock controls when our muscles are most ready for action. This is why some people perform better in sports at certain times of the day.
- Blood pressure: Light helps regulate the hormones that control blood pressure and blood flow.
- Body temperature: Our body temperature rises and falls throughout the day, depending on our activity levels and metabolism, which are also controlled by the body clock.
- Handling medicines: The body clock controls how our organs, like the liver and kidneys, process drugs and toxins, which is why the time of day you take medication can affect how well it works.
Why Morning Light Matters
So, what does all this mean for you? Getting enough morning light is one of the best ways to keep your body clock running smoothly.
When you get outside in the morning and expose yourself to natural light, you’re helping to set your body up for a good night’s sleep later.
Morning light also has other benefits, like improving your mood and reducing your risk of health problems like obesity.
If you want to feel better throughout the day, try increasing your exposure to morning light. Take a walk outside, have breakfast on your porch, or open the blinds to let in more sunlight.
The more light you get in the morning, the better your body can function throughout the day.
Conclusion
Light plays a huge role in regulating our body’s daily functions. From helping us know when to sleep and wake up to controlling digestion and focus, light affects almost every part of our body.
By understanding how light works with our body clock, we can make simple changes—like getting more morning sun—that will help us feel better and stay healthier.
