The Insidious Light of Your Phones

Smartphones have dramatically changed how we live. From how we work, how we communicate to how we play, smartphones are incredibly useful, but could they be causing us harm?

Smartphone screens – like those on laptops, tablets and televisions emit blue light, which is the type of light that the brain interprets as daylight. Your body is finely tuned to its environment and factors like the time of day, the temperature etc. all influence how it adjusts and adapts.

Sleep Disruption

The blue light from your phone’s screen suppresses the production of the hormone that lets you sleep at the end of the day. This hormone, melatonin, affects your circadian rhythm and production increases as the day gets darker and you prepare for bedtime. The result of blue light from your phone is that your brain gets stimulated all the time. This is fine if you are looking at your smartphone screen at noon, but if you are using your phone at midnight, your brain gets confused and thinks it is daylight, making it even tougher to fall asleep.

In the long term, not getting enough sleep can lead to a build-up of neurotoxin making it even harder for you to get good sleep.

Obesity risk

By disrupting melatonin, blue light can also disrupt the hormones that control hunger and may increase the risk of obesity. Melatonin moderates the action of several key metabolic hormones such as insulin, ghrelin and leptin. These hormones manage how hungry you feel, tell you when you’re full and store excess food for future use.

Eye fatigue

Staring at smartphones too long reduces blinking rates and causes digital eyestrain, which leaves the eyes irritated, dry and fuzzy.

Memory, learning and concentration

A poor night’s sleep can make it harder to learn and to remember what you already knew. Some new research also shows that simply having your smartphone nearby reduces your ability to focus and learn new things.

Prostate & breast cancer

There’s a connection between exposure to blue light at night, the reduced production of melatonin and an increased risk of prostate & breast cancers. Research shows that melatonin can help to slow or stop the growth of cancer cells.


People whose melatonin levels are suppressed and whose body clocks are thrown off by light exposure are more prone to depression.

What you can do

  1. Reduce screen time at night

The ideal scenario is to reduce the amount of time you spend exposed to a screen at night. This includes phones, laptops and even televisions. Spend less time in front of a screen and you drastically reduce the amount of blue light you get exposed to.

  1. Use a blue light filter

Many devices now have settings that allow you reduce the amount of blue light that is emitted. This is called ‘night mode’ in some devices and you can set it to turn on at specific times of the day, say  at 6 pm.

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