Natural Light vs Artificial Light: Why Your Body Knows the Difference (Even If You Don’t)

Light does more than help us see: it quietly influences nearly every part of our wellbeing. From how well we sleep to how focused we feel during the day, the kind of light we’re exposed to matters more than you may realize.

Understanding the difference between natural light versus artificial light is the first step in reclaiming your energy, mood, and sleep quality.

What’s the Difference Between Natural Light and Artificial Light?

Natural light, originating from the sun, offers a full and dynamic spectrum that changes throughout the day and plays a crucial role in regulating our biological functions and maintaining overall well-being.

In contrast, artificial light is a man-made source designed for flexibility and consistent illumination. Still, it often lacks the complexity and health-supporting qualities of natural sunlight, which can make a noticeable difference in how our bodies and minds respond to our environment.

Here’s a quick breakdown of the key differences between natural and artificial lights:

• Spectrum: Natural light includes the full spectrum of visible wavelengths plus beneficial ultraviolet (UV) and infrared. Most artificial lights emit a narrow range of light, often rich in blue wavelengths.
  
• Intensity: Sunlight is much brighter than indoor lighting, even on a cloudy day.
  
• Color temperature: Natural light shifts color throughout the day (warm in the morning and evening, cool midday). Artificial lighting often stays the same unless intentionally adjusted.
  
• Impact on health: Natural light supports circadian rhythm, hormone balance, and vitamin D production. Poor lighting can disrupt sleep, strain eyes, and affect mood.
  
• Origin: Natural light is free and abundant (when you’re outdoors in the daytime). Artificial light is available on demand but can come with trade-offs.
  

How Light Affects the Human Body

Light isn’t just visual. It’s biological.

We have specialized cells in our eyes that detect light. These cells aren't just for vision, but also to send signals to our brain about the time of day. These signals help regulate a biological process called our circadian rhythm.

Circadian rhythm is your body’s internal 24-hour clock that tells you when to feel awake and when to get sleepy. And light is its biggest influencer.

Light and Circadian Rhythm

Morning light (preferably natural!) helps reset our circadian clock each day. It signals the brain to stop producing melatonin (the sleep hormone) and boost cortisol (which gives us energy and focus).

In contrast, exposure to artificial blue light at night, particularly from screens, can confuse the brain, delaying melatonin release and making it harder to fall asleep. Check out our other blog posts that discuss how blue light and technology impacts the circadian rhythm and sleep.

Hormonal Impact of Light: Melatonin and Vitamin D

Light has a physiological impact on hormones: 

• Melatonin: This hormone helps regulate sleep. It naturally rises in the evening to induce sleep, unless blue light exposure blocks its production.
  
• Vitamin D: Sunlight on skin helps our body produce vitamin D, essential for immune function, bone health, and mood. Artificial light doesn’t provide this benefit.
  

Getting enough natural light during the day and reducing blue light at night helps keep both melatonin and vitamin D in balance.

Mood, Sleep, and Mental Performance

A lack of sunlight, and the vitamin D production it triggers, has been linked to seasonal affective disorder (SAD), which strikes during the darker months. Natural light boosts serotonin, a feel-good neurotransmitter that helps regulate mood. 

Research has even found that light can be used as an effective and noninvasive therapeutic option to improve sleep quality, cognitive performance, and overall well being. In short: more sun, better days.

The Importance of Light in the Workplace

It's apparent that light, and specifically natural light, is important to your overall health. And considering that most adults spend their time indoors and at work, and that working hours coincide with peak daylight hours, what sort of impact does that have?

Most offices don't have the best lighting conditions, being lit with bright overhead lights, and rarely with natural light in mind. Research out of Cornell University determined that natural lighting was what employees valued the most in an office environment, with benefits including: 

• Better concentration and fewer mistakes
  
• Improved mood and reduced stress
  
• Enhanced sleep quality (thanks to early-day light exposure)

While working near a window is better than relying solely on artificial light, indoor sunlight filtered through glass doesn’t provide the full spectrum or intensity of natural sunlight,  especially the UVB rays needed for vitamin D synthesis. That’s why stepping outside during the day, even for a few minutes, can make a real difference.

Lighting your environment thoughtfully, and being intentional with your light exposure throughout the day, can have a big impact on your performance, comfort and mood.

Common Side Effects of Poor Artificial Lighting

Artificial lighting isn’t inherently “bad”. It’s just often used in ways that don’t support our natural biology. Some common effects of poor lighting include:

• Eye strain and headaches
  
• Fatigue and brain fog
  
• Sleep disturbances
  
• Lower mood and motivation
  

The worst offenders? Bright, cool-toned lights at night, and low, dim lighting during the day. Those are actually the opposite of what our bodies need.

The Problem with Artificial Light at Night

Our screens (think phones, tablets, computers) emit high amounts of blue light. In the evening, this disrupts the natural wind-down process our brains rely on to prepare for sleep.

Blue light, compared to the rest of the visible light spectrum, is shorter in wavelength and thus higher energy. This combo of short waves and high energy means it can penetrate into the eye further than other light, potentially leading to discomfort and in the long term, potentially damage. Even during the day, excessive blue light can damage your eyes and retina. 

Blue light glasses, and screen filters can help reduce exposure, especially if you need to be on a device at night. So can apps that warm your screen color after sunset.

Curious if they work? Yes, when worn consistently, blue light glasses can help support melatonin production and reduce eye strain. Learn more by checking out our other blog which details what blue light glasses are.

Eye health supplements can also promote eye health and support visual function, especially when staring at high energy light sources all day. Look for ones like the Lightbody Eye Health + Blue Light Filter supplement that have Lutein, Zeaxanthin, and maqui berry extract for antioxidant support, blue light support, and hydration.

Why Natural Light is Better for Your Health

Simply put: natural light is aligned with how we evolved to function. From cavemen to the modern man, humans have been using the same light source for years: the sun!

Natural light syncs our biological rhythms, helps us feel alert during the day, and lets us sleep better at night.  Regular exposure to natural daylight can:

• Improve your mood
  
• Sharpen your focus
  
• Enhance sleep quality
  
• Strengthen your immune system
  

Even short walks outside or working near a sunny window can be the difference maker.

Light Needs at Every Age

Children, teens, adults, and older adults all need light, but in different ways.

• Kids and teens need lots of morning light to help regulate sleep and learning.
  
• Adults benefit from mid-morning sunlight to stay energized and focused throughout the day.
  
• Older adults may need more intense light exposure during the day to support sleep and prevent mood disorders.
  

Designing for Better Light Access

Architecture and home design can greatly influence how much natural light we’re exposed to. Look for ways to:

• Increase window exposure. While not as good as unobstructed sunlight, consider putting your WFH setting near a window.
  
• Use light-colored walls and reflective surfaces.
  
• Spend time in rooms that get morning or afternoon sun. It can be a real difference maker if your bedroom is east-facing and receives morning light.
  
• Be mindful of the type of artificial light sources you opt for. Though LEDs and fluorescent lights may be more energy efficient, incandescent bulbs in lamps emit light that is warmer, and better for evening hours.

Even in urban areas, small shifts in how you design your space can help maximize natural light and reduce reliance on harsh lighting.

A Final Note on Light Pollution

While not directly tied to indoor lighting, urban light pollution (the excess of artificial light in urban environments) can affect sleep quality and well being. If you live in a city, blackout curtains and minimizing indoor light at night can help create a healthier sleep environment. 

Support Your Body with Better Light Choices

Natural light is essential for our health and wellbeing. It regulates our sleep, boosts our mood, and helps us function at our best. But when sunlight is limited, especially during darker months, we can still make smart choices to support our circadian rhythm and energy levels:

• Get sunlight when you can, especially in the morning. A 10-minute walk outside in the first hours of the day can have a positive impact on your sleep and wellbeing.
  
• Minimize screen time or use blue light protection in the evenings. Incorporate blue light glasses, physical screen filters, and night-shift brightness settings on your devices to decrease the impact of blue light.
  
• Create a light-friendly, well-lit environment at home and work, and take outdoor breaks when possible.
  

Digital wellbeing isn’t just about limiting tech usage. It’s about using light mindfully to live, sleep, and feel better. At DefenderShield, we're here to help illuminate your journey with science-backed tools and guidance that support your lifestyle every step of the way.