I recently purchased a new Smartphone. While going through its features, I found a setting for a Blue Light Filter. Apparently, this feature cost me slightly more compared to the models without it. This got me thinking. Do I, a colorblind person who cannot even differentiate blue from green, really need this feature? Was the extra money really worth spending on something I cannot even see?

Blue light is one of the seven-colored lights,which together from white light, is emitted by the sun.

  • red (R)
  • orange (O)
  • yellow (Y)
  • green (G)
  • blue (B)
  • Indigo (I)
  • violet (V)

This is also known as the EM spectrum of visible light. At the end of the spectrum is the Ultra Violet light, which is the most harmful and cannot actually be seen. Blue light, being close to the UV light, makes it one of the most powerful and harmful. But how can light be powerful you may ask? EM waves emit energy and it is this energy that the brain perceives as colored light, depending on their variable wavelengths.

Coming back to the blue light, which actually has a small wavelength, after being emitted from the sun, the blue light collides with the air particles and scatters everywhere. This is actually the reason why the sky is blue! The brain’s light receptors capture these blue lights and prompt the difference between day and night: like the perception of energy, remember?

Blue light and the human body

Ideally, our eyes are not capable of dealing with the natural blue light present in the environment. On top of that, the blue light emitted by the LED display devices is even worse than that emitted by the sun. It causes eye damage and fatigue. In comparison with the other colored lights, which get absorbed by the cornea, blue light, due to its high energy passes straight through the natural light filter and hits the retina directly, causing deterioration.

If that was not bad enough, because our brain depends on the natural blue light from the sun to differentiate between day/night, spending time on LED display devices fools the body to keep you awake. This is one of the leading causes of insomnia and deterioration of the quality of sleep.

Our body secretes a hormone called MELATONIN. The secretion of this hormone prompts our body to sleep. However, since our brain cannot differentiate between day and night, the production of this hormone drops significantly. Research has suggested that low levels of Melatonin can cause chronic problems such as Cancer and Depression.

What to do?

Most LED illuminated devices use Blue LED, as they are very energy efficient and cheap to produce. To combat this, researchers have come up with a glass that allows other lights to pass through its microscopic ridges while preventing up to 60% of the harmful blue light and 99% of the UV light from passing through. Yellow glass is also cited as a viable alternative, as yellow absorbs blue. So the next time you are presented with the choice spending that extra money on blue light protection, color-blind or not, do not hesitate. Colour blindness is the inability to perceive energy. Some spending on such eye-protective tools might save you from possibly going blind.

–Arjun Chauhan