By now, you have most likely heard about how you should avoid using your phones and tablets before sleep. The light emitted by our gadgets has an impact on how our bodies work. This topic has been around for quite some time, and the debate keeps going. Now, new research has emerged, and perhaps we still don’t know enough about it. Many people recognize this study as a piece of new evidence for this topic, and it may change the course of dealing with this public health issue from now on.

Blue light as a sleep disruptor

Here’s a quick look at how light affects our body. The retina, a soft tissue found behind our eyes, sends signals to our brain and our Pineal gland, which controls the production of melatonin, a hormone that puts our bodies in a state of sleep. Now, the short-waved light that we get from the Sun during the day helps us stay alert, enhances reaction times, and balances our sleep and wake cycle, also known as the circadian rhythm. The problem is that we tend to surround ourselves with blue light during the night through the use of digital household appliances. It was always believed that looking at smartphone screens at night harms our circadian rhythm and keeps us awake, as the production of melatonin is affected by this light. A new study may have dismantled that theory, though. Scientists now claim that the latest tests show that we didn’t understand how this light actually affects us. They claim that the blue light has a comforting effect and makes us sleep better during the night.

The new study and what it shows

Who conducted the study?

The new study was done by scientists from the University of Manchester. The Biology, Medicine, and Health department may have found evidence that contradicts everything we thought we knew. They published their research in 2019, and it has brought new claims to a never-ending debate about the effects of blue light.

What were the results?

Doctors from the University of Manchester claim that blue light has a far less significant impact on us than previously believed. The effect is far weaker than that of the yellow or white light of equal brightness. They say that if we change the ratio of the short and long wavelengths, it will change the brightness of the colours. You can do this by dimming the lights on your devices. This study included testing done on mice. They used special lighting that allows scientists to change the colour without changing the brightness, and blue light had less of an impact than yellow or white light. Dr Timm Brown claims: “Our findings suggest that using dim, cooler lights in the evening and bright warmer lights in the day may be more beneficial. Research has already provided evidence that aligning our body clocks with our social and work schedules can be good for our health. Using colour appropriately could be a way to help us better achieve that.”

Is it definitive proof?

Because there are many studies with different results, we cannot say that this debate has been settled with this new evidence. However, it will help us better understand how blue light affects our bodies. This study can lead to breakthroughs in the future because it can be used as a guideline for future studies. Until there is a consensus on this topic, we cannot use it as definitive proof.

Does this mean I’m free to use my phone before sleep?

You are more than free to use your mobile devices if you follow the advice made by doctors and stick to warm and bright colours during the day, but switch to cool-toned lights during the night. All modern phones have filters that will help you reduce the brightness of the screen. Use it properly, and it will reduce eye strain and help you fall asleep quicker.

Do we know enough about this?

Even though this study made quite a few people change their stance on the topic of blue light, it didn’t provide a satisfying conclusion for others. Many believe that there is much more research to be done before we can claim anything confidently. The more scientifically inclined are waiting for several new experiments that would either back up or dispute this new evidence. Only once there is a significant body of evidence can we fully explore the facts presented by either side of the argument. What we can say is that there is much more to learn about blue light and that you shouldn’t make any drastic changes until there is enough hard physical evidence to inform your decision.


The negative effects of blue light were brought to the public eye through diligent research, but it seems that we just didn’t have the full picture and still don’t. There’s still more to learn, but at least we know that there are ways to limit the negative effects of staring at our smartphone screens. By using proper precautions, you can feel safe using your devices during the night. Like we mentioned above, there are filters on your devices that help you avoid exposure to specific wavelengths and prevent the impact on your quality of sleep. Use these studies as a word of advice, and experiment with your body. Because our bodies are all different in their own way, you can find what suits you best. Stick with what you are comfortable with, and overcome this modern-day issue one step at a time.  
May 17, 2021