Rather than relying on the artificial environment of windowless laboratories, researchers this time took their participants straight out into the field. The 2025 British study Relationships between light exposure and aspects of cognitive function in everyday life examined the effect of light on the human brain under the real-world conditions of an ordinary day, using high-tech Spectrawear wristbands. The resulting data clearly confirmed that, compared with dim domestic or office lighting, daylight can speed up cognitive responses by 7 to 10 %.
The intensity of the light we have been exposed to over the preceding 30 to 120 minutes affects the speed of our thinking. At levels corresponding to natural daylight, reaction times shorten by 7 % in alertness tests and by as much as 8 % in working memory tests. Daylight also reduces feelings of sleepiness.
Sufficient daylight is not merely about helping us open our eyes in the morning: above all, it is a long-term investment in our energy throughout the day. A well-aligned circadian rhythm then ensures sustained attention, better memory and faster reactions. And when we are unable to spend enough time outdoors, a suitable alternative may be pro-cognitive lighting, whose spectrum closely approximates that of natural daylight and which supports conditions for concentration, alertness and a healthy circadian rhythm.
Read the full study HERE.
This article was translated with the assistance of AI.
