How lighting affects performance

Colour temperature

Color temperature is a physical concept that expresses the intensity of radiation from a light source. It is measured in Kelvin (K) and is always indicated on the lamp packaging.

Different color temperatures are perceived differently by the brain and trigger different processes in it.

The lower the temperature, the closer the light is to the red spectrum. The yellow light is relaxing and calming. The higher the temperature, the closer the light is to the blue spectrum. Such light, on the contrary, invigorates. To correctly position light sources in the room, you should remember about this feature.

The table will help to understand how this or that color temperature looks in nature and where it is used in life.

Temperature, K	Shade	In nature	Application
2 500–3 000	Warm orange	Sunrise	Creating a cozy atmosphere
3 000–4 000	Warm yellow	Sky two hours after sunrise and two hours before sunset	Relaxing light
4 000–5 000	Neutral white	Midday sun	Daylight for work
5 000–6 500	Bluish	Overcast sky	Demonstration of items

Lamp color rendering

The color rendering of the lamp determines how adequate the colors will look in the room. Low color rendering lamps distort color perception, which also affects performance.

This parameter is indicated on the package by the index Ra or CRl. The higher the index, the more natural the colors appear in the room. Incandescent and halogen lamps have the highest color rendering. Good color rendering - fluorescent lamps with a five-component phosphor, MGL (metal halide) lamps and modern LED lamps.

The best lighting is natural

The best light for work is natural sunlight, which we can see at noon. It improves mood, improves concentration and productivity, and fights depression. You've probably noticed yourself how much better you feel on a sunny day.

If you have the opportunity to work by the window, use it, but do not sit facing it. The table should be located with the left side to the window: this way more light will penetrate into the room, and your eyes will not get tired.

The complete lack of access to natural light leads to negative consequences. According to the Impact of Windows and Daylight Exposure on Overall Health and Sleep Quality of Office Workers: A Case-Control Pilot Study, employees working in windowless spaces sleep on average 46 minutes less than those working in offices with windows. Lack of sleep and disturbed circadian rhythms lead to decreased productivity and overall vitality.

Lighting for productive work

Since access to sunlight is limited by natural causes, it is replaced with artificial lighting. The closest to it is neutral white with a temperature of 4,500-5,000 K. Just like the midday sun, it increases concentration and relieves fatigue.

In this case, the light should be evenly distributed over the entire working area and fall exactly from above. Otherwise, it will create shadows or blind the eyes, which will reduce performance. It is better not to use a table lamp without general ceiling lighting, as harsh light contrasts tire the eyes.

Lighting for negotiations and meetings

Cool yellow light with a temperature of 3,500–4,500 K simultaneously maintains a working mood and relaxes. Therefore, this lighting is used in conference rooms.

Very warm lighting, less than 3,500 K, is placed in meeting rooms and recreation areas. It evokes a feeling of comfort, relaxes and sets up confidence. Homes use the same light in living rooms, bedrooms and over the dining table to create a cozy atmosphere. You won't be able to work productively under such lighting - you will fall asleep. In addition, too dimmed light increases eye strain and can provoke headaches.

Change in color temperature throughout the day

Working in cold light throughout the day is tiring and leads to decreased performance and disruption of circadian rhythms. Therefore, as fatigue builds up, it is better to move to relaxing areas with warm lighting or use dimmers to reduce the light intensity.

Gadgets also have to switch the color temperature. In the morning and during the day, adjust the backlight as you like, and in the evening switch to "Night mode". To do this, install a blue light blocking app or search for "Night mode" in the settings. This will save your eyes and help your body prepare for sleep.