Blue Light Filters: Exactly How They Work

A question we frequently hear is - how do blue light filters work? As you are reading this article on either your smartphone, tablet, or computer, you are currently being exposed to blue light. This is emitted from all digital devices. If you have read our other articles, you will be aware blue light can cause significant long and short-term damage to your health.

In short, Blue light exposure can cause eyestrain, headaches, fatigue and sleep problems which will inevitably impact your daily productivity and mood. Blue light exposure can also lead to serious long-term health issues. Such as by increasing the risk of depression, heart disease, obesity, and macular degeneration, which leads to vision impairment.

Here's an infographic on how limiting blue light can improve your life, rounding up this post if you prefer visuals.

Health Risks From Not Having a Blue Light Filter

These health risks have led us to develop anti-blue light filters for digital devices which block blue light and reduce the risk of these health issues. So, now we are aware of the dangers of blue light, the question is - how do blue light filters work?

Firstly, it is important to note that there are different types of blue light filters. There are a variety of blue light filtering products on the market, and many phones will give you the option to shift to night mode.

Many smartphones' anti-blue light settings are named 'night mode' due to the added importance of protecting yourself from blue light in the evening. This is because the disruption of your sleep is one of the most detrimental effects of blue light exposure.

Blue light tricks your body clock (or 'circadian rhythm') into believing that it is still daytime. Therefore, our body does not produce the sleep hormone of melatonin. This makes it much harder to fall and stay asleep. Inevitably, this leaves individuals feeling grouchy, tired, and unproductive the following day.

The Science Behind Blue Light Filters

So, how do blue light filters work? Ocushield is a screen protector which includes a medically rated blue light filter. This filter can be attached to your smartphone, iPad or computer. This blocks blue light emissions while retaining the same crystal-clear screen quality and colour at all times.

Contrastingly, 'night mode' filters must often be manually switched on by users (which people often forget to do) and result in an orange tinge. Not great when you want to enjoy a bit of Instagram or Netflix in the evening!

The orange tinge which is emitted from devices in night mode comes as a direct result of the way screens emit light in the first place. This is completely different to the way physical filters, like Ocushield, work. As displayed in the image below, light is made up of electromagnetic particles that travel in waves (which are represented here as different colours). Together these make up the electromagnetic spectrum.

Each wave is a different length and the shorter the length, the greater the energy. Within the visible light area of the spectrum, blue light has the shortest wavelength. This means that it produces a very high amount of energy, which is the reason it can be so harmful to your eyes and health. The reason that night mode causes your phone screen to turn an orange shade is that the blue light spectrum has been actively removed from your display.

However, physical filters like Ocushield do not make your screen appear orange as they instead absorb the blue light which leaves your phone. The result is a blue light-free screen, with none of the discolorations.

The orange tinge which is emitted from devices in night mode comes as a direct result of the way screens emit light in the first place. This is completely different to the way physical filters, like Ocushield, work. As displayed in the image below, light is made up of electromagnetic particles that travel in waves (which are represented here as different colours). Together these make up the electromagnetic spectrum.

Each wave is a different length and the shorter the length, the greater the energy. Within the visible light area of the spectrum, blue light has the shortest wavelength. This means that it produces a very high amount of energy, which is the reason it can be so harmful to your eyes and health. The reason that night mode causes your phone screen to turn an orange shade is that the blue light spectrum has been actively removed from your display.

However, physical filters like Ocushield do not make your screen appear orange as they instead absorb the blue light which leaves your phone. The result is a blue light-free screen, with none of the discolorations.