The evidence just keeps on piling up – excessive exposure to blue light is harmful. Blue light suppresses the production of melatonin, a sleep-promoting hormone produced by the brain’s pineal gland. While this is a welcome effect during the day, exposure to blue light at night suppresses sleep and can lead to insomnia, fatigue and general disruption of the sleep cycle. Furthermore, this lack of sleep can also cause other far-reaching effects on your general well-being. Blue light is also associated with eyestrain and permanent damage to the eyes which may contribute to the occurrence of Age-Related Macular Degeneration (AMD). This is because blue light has the highest amount of energy in the visible spectrum and is, therefore, able to penetrate into the deeper layers of the eye and cause long-lasting damage.
To safeguard our health and protect our eyes, we have to find ways of reducing our exposure to harmful blue light. Blue light filters offer a way of doing just that. So, what is a blue light filter? As the name suggests, they are filters that provide protection from the harmful effects of blue light by blocking or filtering most if not all the blue light reaching our eyes. Blue light filters all fulfil this basic function even if they come in many forms or work in different ways.
Types of Blue Light Filters
1. Natural Blue Light Filter
It may interest you to know that our eyes contain a natural blue light filter. This natural filter is the macular pigment. It’s a yellow spot found in the central layer of the retina in the eyes that protects the macula of the eye which is where light is focused and the image is the sharpest. The macula is also the most photosensitive region of the eye which makes it particularly prone to damage done by blue light, hence the need for a blue light filter in the first place.
True to form, this macula pigment absorbs light virtually only in the blue light spectrum, preventing it from reaching sensitive photoreceptors. However, the macular pigment density and its ability to filter blue light vary from person to person which is why some people are more sensitive to light than others. Fortunately, the amount of macular pigment isn’t necessarily set in stone. You can increase the quantity of macular pigment in your eyes by consuming a diet rich in green leafy vegetables. You could also turn to supplements of the carotenoids which make up macular pigment – lutein, zeaxanthin and meso-zeaxanthin.
However, it’s imperative to consider that many of us have a thin macular pigment and even sufficient macular pigment isn’t enough to completely erase the effect of excessive exposure to blue light. That’s why the other blue light filters are important.
2. Physical Blue Light Filters
This category of blue light filters includes various screen protectors that you can place over the screens of laptops, phones, TVs and other devices that emit blue light. There are also blue-blocking glasses that you can directly wear over your eyes to protect you from multiple sources of blue light including fluorescent lighting and screen LEDs. How much blue light is filtered by physical blue light filters depends on its tint colour, the presence of a blue-blocking coating or other materials within the filter.
The most common blue light filtering tints are yellow, amber and red. As a general rule of thumb, yellow filters tend to block the least amount of blue light but provide the least colour distortion. On the other hand, red filters block all light except. This means that blue light is blocked entirely since it’s farther away from red than yellow in the colour spectrum. As a drawback, red filters have a low visual transmission and more colour distortion. Amber or orange filters usually fall somewhere in-between red and yellow filters. Look at our selection of high-quality screen protectors and blue-blocking glasses here at Ocushield for blue light filters you can depend on.
3. Software Blue Light Filters
This type of blue light filters come in the form of programs that you can install on your phones and computers to reduce the emission of blue light. They reduce this emission by altering the colours displayed by the digital screen of your device. For laptops, there are countless apps like f.lux and NightShift that are sufficient to keep your eyes safe. There are also apps suited for smartphones like Twilight which also reduce the amount of blue light emitted from the screen. However, unlike physical blue light filters, the blue light reduction by software can’t be 100% due to limitations by hardware.
If you were wondering what a blue light filter is, then you have your answer. Blue light filters in all their various forms play a major role in the protection of our eyesight from blue light. So all you have to do is pick a filter that’s convenient for you. If you’re interested in finding out more about blue light filters, you can read various articles on our blog.