Indoor Lighting: How to Choose the Right Light for Your Health

Natural light is light that enters rooms from external sources, such as the sun. It plays a key role in creating a comfortable atmosphere and influences the overall perception of space. Artificial lighting, in turn, is light created by various electrical devices, such as lamps and fixtures. It allows you to adjust the level of illumination in rooms, providing the necessary conditions for work and rest at any time of day. It is important to correctly combine both types of lighting to achieve optimal balance and create a harmonious environment.
When choosing lighting for your workspace and home environment, it is worth considering several key aspects. First, it's important to determine what the light will be used for: reading, working at a computer, or simply to create a cozy atmosphere in the room.
Second, you need to pay attention to the light intensity. The brightness of the lighting should correspond to the tasks performed: it is better to choose brighter sources for work, while softer and warmer tones are suitable for relaxation.
Also, it is worth considering the placement of the lamps. Main lighting, as a rule, should evenly illuminate the space, while accent lights can highlight certain areas, such as a desk or reading nook.
Don't forget about color temperature. Cool shades of light (5000-6500K) promote concentration and alertness, while warm ones (2700-3000K) create an atmosphere of coziness and relaxation.
It is also useful to consider the ability to adjust the brightness. Dimmers or lighting with variable intensity can help adapt the light to specific needs at different times of the day.
The style of the lamps is equally important, as it should complement the overall interior. Choosing the right lighting can significantly impact your mood and productivity in everyday life.
When choosing between cool and warm light, it is important to consider the purposes for which you plan to use the lighting. Cool light, with its blue undertones, is often suitable for workspaces, as it promotes concentration and alertness. It can be especially useful in offices or educational institutions where concentration is required.
On the other hand, warm light, with yellowish and orange tones, creates an atmosphere of coziness and relaxation. It is ideal for living spaces such as living rooms and bedrooms, where it is important to create a comfortable environment for relaxation.
Thus, the preference for one type of light or another depends on your needs and the mood you want to create in a particular space.
The importance of lighting levels cannot be underestimated. Light plays a key role in various aspects of our lives, including comfort, safety, and productivity. Proper lighting creates a cozy atmosphere, helps us focus on tasks, and promotes a positive mood. Insufficient light can lead to eye strain, decreased concentration, and a decline in overall well-being. At the same time, excessive brightness can cause discomfort and irritation. Therefore, the correct balance of lighting is important for creating a harmonious and effective environment in both living and working spaces.
How to properly distribute lighting in a room;
Light pollution is excessive or inappropriate lighting that negatively impacts the environment and human health. It occurs as a result of the excessive use of artificial light, especially in urban areas, where the brightness of streetlights, billboards, and other light sources disrupts natural conditions. Such pollution can lead to various problems, including disruption of human biological rhythms, disruption of animal migration routes, and a negative impact on ecosystems. It's important to recognize that light pollution not only affects the night sky, making it difficult to see the stars, but can also significantly impact the overall quality of life in communities.
What are the consequences of sleeping with the lights on?
What should you do if you can't sleep in a dark room?
Insufficient lighting can significantly impact work efficiency. Poor lighting reduces visibility, making it difficult to complete tasks and increasing the likelihood of errors. Workers may experience discomfort, which, in turn, reduces their concentration and productivity. Furthermore, insufficient light can cause eye strain and headaches, which negatively impacts the overall well-being of employees. As a result, companies may experience decreased productivity and an increase in errors, which ultimately impacts the success of the entire business.

We have launched a Telegram channel called "How are you?" On this channel, we'll share content on self-development, psychology, and how to study smartly and develop your career at any stage of your life in a convenient format. Join us!

The concepts of natural and artificial lighting: what is the difference?

Natural lighting is light coming from the sun. It is available even on cloudy days and continues to exist despite the polar night.

Artificial lighting is light that is created using lamps and various electrical devices. It was Thomas Edison who opened the way to this innovation. The scientist foresaw that his development would have a significant impact on people's lives, and this prediction came true. Nowadays, artificial lighting is available around the clock, which is very useful for business, but not always favorable from a human health point of view.

Lighting solutions for professional activity and home comfort

At first glance, light is just light - you bought a lamp, installed it, turned it on, and that's it. However, when it comes to artificial lighting, there are many details to consider: the direction of the light, its color temperature, and its intensity.

To create not only attractive but also functional lighting in a room, it's worth paying attention to the following characteristics of artificial light.

Color temperature, which determines the degree of whiteness of light, is characteristic of both natural and artificial lighting. This parameter is measured in Kelvin (K) and ranges from 1000 K, which corresponds to warm yellow light, to 10,000 K, which produces cool blue light. At the middle level there is white light.

Image: Kolokno / iStock

Photo: sergeyryzhov / iStock

Cold light

🔵 More than 5300 K

Cold light activates the body due to the sensitivity of the photoreceptors located in the retina. When this cold daylight or artificial light reaches the photoreceptors, they send a signal to the brain, saying: "Time to wake up." As a result of this process, the level of melatonin, which is responsible for sleepiness, rapidly decreases, while the concentration of norepinephrine and cortisol, necessary for wakefulness, increases.

Warm Light

🟡 Less than 3300 K

Remember the emotions evoked by a magnificent sunset. Watching the yellow-orange hues in the sky brings pleasure, as warm light helps increase melatonin levels and decrease cortisol in the body. A similar state can be experienced under the light of an orange lampshade or near burning candles and a fireplace.

Cold morning and warm evening light are completely consistent with the human biological clock. Changing the color temperature of natural light affects our circadian rhythms, regulating sleep and wake patterns.

Which color in the interior is preferable - warm or cool?

The optimal color temperature for each room is individual.

Walk around your home and take notes on the purpose of each room. For example, in the living room, you might watch movies, read books, or spend time with children. Perhaps it is also used as a workspace. In this case, you can place lampshades with soft light next to the sofa, and a table lamp with cool light on the work desk. Do the same for the kitchen and other rooms.

When choosing lighting for different rooms, it is important to consider the functional features of each room, as well as the atmosphere you want to create.

For the living room, soft, diffused light sources are suitable, which will create a cozy atmosphere. Here, you can use wall lamps, floor lamps, or dimmable chandeliers to adjust the brightness depending on the time of day and your mood.

The kitchen needs bright, directional lighting to ensure comfort while cooking. Spotlights or pendant lamps above work surfaces are the best choices. It is also helpful to install backlighting for cabinets and shelves.

In the bedroom, choose warm, calming light to promote relaxation. Wall sconces and nightlights will help create a romantic atmosphere and also provide soft light for reading.

In the bathroom, it is important to consider moisture-proof lamps that will provide sufficient illumination and safety. It is important that the light is bright but not glaring, so it is best to use combined light sources, such as ceiling lamps combined with mirrored lighting.

A hallway or entryway requires thoughtful lighting to visually expand the space. Ceiling or wall-mounted lamps are suitable, illuminating the way and creating a sense of spaciousness.

Therefore, when choosing lighting for each room, you should consider both functional and aesthetic aspects to create a comfortable and harmonious atmosphere in your home.

When choosing a light bulb, you've probably encountered the terms "lumens" and "lux," which can be seen on packaging. Lumens indicate the total amount of light emitted by the bulb, while lux indicates the brightness with which this light illuminates a specific area. To achieve an illuminance of 1 lux, it is necessary to evenly distribute 1 lumen of light over a square meter of surface. Thus, the illumination level depends both on the wattage of the bulb itself and the area to be illuminated.

One lux measures the level of illumination corresponding to the light of a full moon. As for sunlight during the daytime, its intensity can reach 100,000 lux. In cloudy weather, this figure is significantly reduced and is only 100 lux.

Here are some illustrations of what kind of lighting may be needed in a living space.

Recommended illuminance values (in lux) [1]:

Installing lamps that emit intense directional light on the floor is not practical. Light that is reflected from the floor surface or emanates from it is perceived by our eyes as harsh and unpleasant, since the lower eyelid does not have sufficient protection from glare and is transparent [6].

💡 Recommendation: To avoid glare in a room, try not to direct light from lamps onto reflective surfaces. Exceptions include LED strips placed above baseboards, as well as diffused light from floor lamps directed toward the ceiling. These types of lighting, on the contrary, are quite useful – they visually enlarge the space and add a multi-layered effect when combined with sconces and table lamps [1].

The color rendering index (CRI) reflects the degree of accuracy with which colors are perceived using artificial lighting. This indicator ranges from 0 to 100, where 100 represents the highest accuracy, comparable to natural sunlight.

For example, street lamps with orange light often have a rather low CRI, which is why colors appear dull or distorted. See for yourself: look at your clothes under such lighting – you will notice that the colors become completely unnatural.

An increase in this CRI helps the perception of colors become closer to how we see them under natural sunlight. This is not only pleasing to the eye, but also has a positive effect on overall visual perception: colors appear more saturated, objects acquire a bright contrast, and the surrounding space seems to be filled with life.

The color rendering index is not directly related to the color temperature of the light source. For example, even if a lamp claims that its light corresponds to a warm temperature of 2800 K, the perception of this light by the human eye will be determined by the color rendering index.

The cold morning light and the warm sunset light are completely in line with our body's biological clock. Changes in the color temperature of natural light affect our circadian rhythms, which determine sleep-wake cycles.

Definition of Light Pollution: What is it?

Light pollution is excessive or incorrect use of artificial lighting at night. Approximately 83% of the world's population and over 99% of residents of the United States and Europe face this problem. Singapore ranks among the world's worst countries for light pollution, and its residents are exposed to skies so bright that their eyes can't fully adapt to the darkness.

The Effects of Sleeping with the Lights On

At night, the sun doesn't emit light, and artificial light sources are designed to mimic this. However, about 40% of people choose to fall asleep with a bedside lamp or TV on. Phyllis Zee, director of the Division of Sleep Medicine at Northwestern University Feinberg School of Medicine, believes this is highly unsafe.

Together with colleagues, Zee conducted a study on the health effects of sleeping under artificial light. Participants were divided into two groups: one group slept under 100 lux, which corresponds to moderate light, and the other under 3 lux, which is considered dim light. The study found that moderate light activates the body, which can be compared to a state of wakefulness or even a feeling of urgency. People sleeping under such light experienced an increase in heart rate, which in turn increases the risk of weight gain and diabetes. Nighttime light, especially cool-toned light, can disrupt the functioning of our body's "master clock," which is responsible for sleep and wakefulness. This "clock" is a group of 20,000 nerve cells located in the hypothalamus. This region of the brain regulates such important processes as appetite, body temperature, emotional state, sexual behavior, and hormonal balance. This entire complex of functions can be jeopardized by just one light bulb turned on at night.

The Impact of Insufficient Lighting on Employee Productivity in the Office

A study conducted at Northwestern University in Chicago revealed interesting results: workers located near windows receive more light during the day. 173% more natural light and sleep almost 46 minutes longer each night. At the same time, those who work in windowless offices are more likely to report fatigue, difficulty concentrating, and sleep disturbances. Thus, employees located near windows demonstrate higher productivity and better well-being.

High-quality lighting helps speed up mental task performance by 20% [12].

To ensure high-quality lighting throughout the day:

Favor rooms with windows facing the street and where there is sufficient sunlight.
Use appropriate shade devices, such as adjustable blinds or curtains, to minimize glare. Remove shading elements when they are not necessary.
If daylight is insufficient, use electric lighting to achieve optimal illumination levels both at workstations and at eye level.
When using artificial lighting, it is important to keep the light bright and cool white from mid-morning to early evening. After that, in the late afternoon, you should reduce the brightness and switch to a warmer white.

Sources

Rayberg K. Lighting Your Life: The Art of Using Light for Health and Happiness. Hachette UK. 2018.

Harley S. and Brinsmead N. Warn about one common mistake that is ruining the lighting in your home office. Homebuilding. 2025.

Lin J., Ding X., Hong C., Pang Y., Chen L., Liu Q., Zhang X., Xin H., and Wang X. Investigation of various biological benefits associated with the use of low color temperature LEDs as the main lighting source in indoor environments. Scientific Reports. 2019. 9(1). DOI: 10.1038/s41598-019-43864-6.

Y. Hu and T. Akiya conducted a study concerning the effects of illuminance level and color temperature of ambient lighting on psychophysiological performance during paper- and computer-related tasks. The results of their work were published in the journal «Building and Environment» in 2022, in issue 228, under article number 109796. DOI: 10.1016/j.buildenv.2022.109796.

Jung, C. M., Khalsa, S. B. S., Scheer, F. A. J. L., Cajochen, C., Lockley, S. W., Czeisler, C. A., and Wright, K. P. examined the immediate effects of bright light exposure on cortisol levels. Their work was published in Biological Rhythms in 2010, including issue 25(3), pages 208–216. DOI: 10.1177/0748730410368413.

Bates, P. A. (2024, February 20). Natural and artificial light in indoor environments. Scientific American.

Falchi, F., Cinzano, P., Duriscoe, D., Kyba, C. C. M., Elvidge, C. D., Baugh, K., Portnov, B. A., Rybnikova, N. A., and Furgoni, R. present a new global atlas of artificial night sky luminance. Scientific Advances. 2016. 2(6). DOI: 10.1126/sciadv.1600377.

EXPAND LIST

Dim your windows while you sleep to take care of your health. Northwestern Now.

Study links workplace lighting to better sleep and increased vitality. Psychology Today.

Which color of light helps you sleep better? Sleep Foundation.

Bergland, C. Study links workplace light exposure to better sleep and increased energy. Psychology Today. 2013.

Research conducted in primary schools on natural light and productivity has been published by the European Council for Energy Efficiency.

Ticleanu, C. The impact of home lighting on human health. Lighting Research and Technology. 2021. 53(5). 453–475. DOI: 10.1177/14771535211021064.