Smartphone Night Modes May Be Designed Backwards

Newly published research shows that your phone’s blue light might be less of a problem for disrupting sleep patterns than previously thought. A study conducted by University of Manchester scientists found that the impact on sleep patterns is weaker when using phone displays with blue colors than it is with bright yellow colors. The results of the study have been published in science journal Current Biology and is free to read online.

Night modes and dark themes have seen a surge in popularity in mobile and desktop apps over the past few years, the idea being that reducing blue light would reduce sleep disruption. This was based on earlier research that discovered a protein called melanopsin in the eye was linked to the body clock and was more sensitive to the blue end of the visible light spectrum. Therefore, to make displays less stimulating at late hours, blue colors were avoided and replaced with warmer yellow tones.

Now, the University of Manchester’s Centre for Biological Timing has found that blue light may be more conducive to sleep than yellow light is and that the level of brightness has a bigger influence on your body clock. Using a mouse model, the researchers discovered evidence that yellow light wavelengths disrupt the sleep pattern even more than blue light. The body clock uses the dim and blue appearance of twilight to determine when to sleep, so looking at cooler-colored lights in the evening and warmer colors in the daytime mimic nature more accurately than the other way around.

It’s important to note that the study was conducted with mice under adjustable LED lights, rather than with humans using phones. However, if this research can be proven to work with human subjects, it could lead to future versions of night modes and dark themes being designed in almost the opposite way that they are currently.