Light is way more complicated than what most of us know for sure. Everything that we see day to day, from the sun, to lamps, to our phones exposes our eyes to some alteration of light. Some we see, which are called visible light, and others like x-rays and ultraviolet light are invisible. We all know about the invisible ultraviolet light as it is the same component of sunlight that tans our skin and, if we are not careful, burn it. But some do not know about the perils caused by visible light and in particular, blue light. In this article we will talk about blue light and if it is truly bad for us. And then we will talk about blue light blocking glasses and try to figure out if there is a truly a need for it.
What is Blue Light
First things first, let us try to understand exactly just what blue light is. Sunlight, or white light for that matter, contains colors which are familiar to us: red, orange, yellow, green and blue. Lining up these colors along with various shades of each gives us the light spectrum. And the combination of all visible light will produce white light.
Each color represents a waveform that produces a specific light depending on the amplitude or height of the wave. It also signifies the energy level in each wherein a shorter waveform means a higher energy level. The ones on the red end of the light spectrum show the lowest energy of all the light while, the ones at blue end show the highest.
The invisible light beyond the red end of the spectrum is called infrared light which can raise the temperature of what it is directed to. An example of this are warming infrared lamps which makes us feel cozy despite not emitting anything visible.
At the other end are ultraviolet light which, at extreme conditions, could be harmful to us and cause burns, unwanted tan lines, and even cancer. These are lights with short wavelengths that we can get from sunlight, and tanning studios.
Facts about Blue Light
It is Everywhere
While we often see blue light as a peril directed to us by man made electronic devices such as phones, television, and computers, the reality is you could not end a day without being subjected to blue light. Sunlight is the main source of blue light and almost being a monopoly at that. The light that we receive from anything else pales in comparison to sunlight.
This is not concerning however, because blue light from the sun that exposes us to a finite amount of time is natural for humans. We have adapted to this level blue light and we are able to shrug it off. In fact, we need a certain amount of blue light in our day to day activities. Blue light triggers a response in our brain that allows us to be more active. It sends a signal telling us that it is time to wake up.
What is concerning is the blue light that comes from our electronic devices that we have not adapted to yet as a specie. A little under a century and a half ago, humans did not know of light emanating from anything else that is not caused by a fire. This meant that we were not subjected to any other form of blue light from sunset to sunrise. Today, we are subjected almost 24/7 to various sources of blue light right from the devices we keep in our pockets, computer screens at work and television right before going to bed.
Our Eyes Need Help
The adult human eye is quite adept in blocking UV rays by preventing it from directly affecting the light-sensitive retina using the anterior structures cornea and the lens. This does not mean that there is no need for sunglasses, however, as other parts of the eye are not as secure. On the other hand, the eyes do not have mechanisms to block out blue light. The cornea and lens does not consider blue light to be harmful, and slips right through them.
Dangers of Blue Light
Over exposure to blue light could cause macular degeneration. Because blue light bypasses the cornea and lens, the retina is at risk to damage due to its nature of being light-sensitive. At the worst case, constant exposure to any form of blue light can even cause vision loss.
There is however, still unanswered questions as to how much exactly is too much for our eyes in terms of blue light subjection.
Eye strains refers to any strain that is directly caused by discomfort in the eyes. Because blue light, penetrates our eyes with higher energy levels and scatters more, it is not easy for our eyes to focus on them. When we use our digital devices such this loss of focus tends to put stress our eyes and cause digital strain.
Blue light blocking glasses have been shown to be able to block out the scattering of blue eyes and may significantly decrease eye strain. When using a computer for a long amount of time, especially during the night, yellow tinted glasses that block out blue light can help reduce the noise and thus reducing eye strain.
After a cataract surgery, it might be more important to block out blue light as the operation causes us to lose all natural affinity that we have with it.
Is it all bad for you
As was mentioned above, blue light serves a purpose in our day to day lives and it has been observed that losing all access to blue light causes us to feel more tired. While blue light blocking glasses helps us to get things done at night time without having to suffer from eye-strain, it actually allows our body to slow down and prepare itself for sleep. This is the vital function of blue light in that it serves to regulate our sleep.