Monitors and smartphones today include a feature called a blue light filter. This solution is designed to reduce the emission of said light, which is harmful to sight and generates eye fatigue. There are also glasses that have this filter. But why does the color change when we activate the blue light filter?
Spending many hours in front of the computer screen is not good for our health. Many will notice after a few hours that they feel something, such as discomfort or itching in the eyes. Some will notice a bit of tearing and some even a headache. All this is caused by the emission of this light that is unavoidable, although it can be mitigated.
Chromatic aberration, a very important parameter
There is a very important parameter in monitors, and that is color accuracy . To define it in a simple way, it is the deviation that exists between the colors that the monitor shows us and the real color. A parameter that for a video game fan can be relatively important. But, those who are dedicated to photo and video editing, take it into account.
This difference between the color displayed on the monitor and the actual color is called chromatic aberration . For this chromatic aberration, there is a color standard called Delta E. The lower the value, the greater the color forecast that the monitor offers.
If the value is: Delta E<2 , it indicates that the color displayed by the monitor is indistinguishable to the naked eye from the real color. But, when value is: Delta E>5 , there is a more than obvious difference. Both for professional users and for video game fans, this parameter is of great importance.
Monitors that focus on professional design will always have one value: Delta E<2 . On the other hand, we have monitors focused on offering a good color range, such as gaming monitors where the value will be: Delta E<4 . Finally, the bulk of monitors on the market and laptop screens are usually between: Delta E>3 and Delta E<6.
The problem is that when we buy a monitor with a blue light filter and activate it, we will see that there is a considerable deviation from the Delta E value, increasing it considerably.
Why does the color change so much with the blue light filter?
As it turns out, the deviation in color accuracy is directly related to the light source of the screen. Screens are currently based on LED panels . The problem is that blue light represents a very large spectrum in LEDs. But in addition, the debugging process of these is complex and usually generate problems.
There is not always a sharp color change with the blue light filter. When blue light filtering is done at the software level , color drift can be mitigated quite a bit. This is because the signal is processed before the image is generated and the blue light is “removed”.
This method filters blue light in all bands. When this filtering is activated, the image on the screen turns yellowish and seems to turn off, losing brightness . This makes the light output softer and less dazzling.
Usually this blue light filter can be activated or deactivated according to the needs of the user. When not much color accuracy is required, it can be turned on to give your eyes a rest. If precision is required, it is deactivated for a while and that’s it.
Blue light filter glasses
We can find a wide variety of glasses on the market that have lenses with a yellowish tint. What these glasses do is “prevent” the passage of blue light. The problem with these glasses is that they are usually quite expensive and are not designed for users with prescription glasses.
An option for people who wear prescription glasses is to get glasses with this integrated filter. In my case, last summer I had my eyes checked and I got prescription glasses with blue light filters. I must emphasize that this filter was a significant cost overrun. If I remember correctly, it was an extra cost of 80 euros, but spending so many hours in front of the screen, for me it was essential.
