Reduce blue light on computer display after sunset to reduce eye-strain & for better sleep

Whether we like it or not, we live in a fast-paced, digital world in which computers & phones have become ubiquitous, and staring at these device displays even late in the night have become inevitable. Since the displays can be harsh on the eyes during night, most of us follow the advice of using auto-brightness or manually reduce the brightness depending on the ambient light to reduce eye strain. But despite reducing brightness levels, one can notice that the screen still emits an eerie blue glow, which can actually affect the eyes.

laptop_glowRecent research studies have proven that the blue wavelengths, especially those which are emitted from computer/phone screens can affect health when viewed during night because it is against the natural biological process of humans to expose eyes to blue wavelengths after sunset, although the same blue wavelength can result in positive effects during day.

Since Blue is one of the components of the RGB color space (which is the most common format in electronic displays), just reducing the brightness (or using auto-brightness) is not enough to fix this issue because it equally reduces all the 3 components (Red, Green, Blue). A better solution would be to adjust the display by reducing only the Blue wavelength, while retaining the rest of the wavelengths. This is possible by tuning the “Color temperature” settings.

To give an idea of what color temperature is all about, consider different kinds of light sources that you come across in your everyday life, and arrange them into a spectrum where clear blue sky is at one end and fire/flame is at another, with rest of the light sources placed accordingly in the gradient. now try to visualize these colors and associate them with warm/coldness. Thanks to the evolutionary process over thousands of years, our brains are conditioned to associate colors like bluish-white to “cold” and colors like yellowish-red to “warm”.
In digital displays, their default setting is closer towards “cold” color temperature with dominant blue wavelength which is necessary during daytime, but during night, as discussed above, the blue wavelength can be harmful. Hence, the display should be adjusted towards “warm” color temperature during night, which will automatically reduce the blue wavelength, while retaining other wavelengths & reduce impact, strain and improve health.

Following is a photo comparison between default & warm color temperature setting on an electronic display.
Now, how do we adjust these color temperatures and when should we adjust it? Fortunately, we don’t have to break our head over these details because there are software programs which are designed just for this purpose and they run automatically in the background.

f.lux is one such popular software which runs in the background, automatically changes the screen color temperature (to warmer colors) after sunset and reverts to normal colors after sunrise.
It is available for free download for PC & Mac here:

Android users can try the “Easy Eyes” app: