We wake up to our mobile screens, switching off a trilling alarm, checking our notifications; at work, it is at least eight hours in front of the computer; back home in the evening, it’s time for TV. With the pandemic, even socialising had shifted to the digital space. Our world is now always bathed in bright, blue light, wreaking havoc on our sleep cycles that depend on night’s darkness for routine. But, why does blue light specifically pose a risk?

FOR YOUR EYES, BLUE LIGHT IS SUNLIGHT

Blue light refers to a part of visible light of the electromagnetic spectrum, which falls between the 400 to 490 nanometer wavelength. It’s actually strongest in sunlight and is what makes the sky blue. For indoors - LED light, used to illuminate everything from our mobiles and TVs to our homes, emits blue light. According to a 2011 study published in the US-based Journal Applied Physics Letters, white LEDs also actually degrade as time passes, with increasing blue light emission.

HOW DOES IT AFFECT US?

Within our eyes, there is a special set of cells that call the shots on melatonin – your sleep hormone. They are called photosensitive retinal ganglion cells, housed in the innermost layer of the retina and contain the chemical, melanopsin. This is responsible for regulation of melatonin by the pineal gland, which is inside the brain.

According to a 2005 study published in Chronobiology International, official journal of the International Society of Chronobiology, melanopsin is activated most efficiently to suppress your sleep hormone by blue light between 420 and 440 nm.

When you are using screens or digital devices in the night, the body reacts to it as if it is being exposed to sunlight. Your brain is confused actually – it stops producing the sleep hormone, known as melatonin, and you end up not getting enough sleep. It affects our sleep-wake cycle. The effects include reduced sleep quality, duration and waking up during the night. In summary, using blue-light blocking glasses does not mean you will avoid the harmful effects of using mobile devices and screens, but these tips can help:

Minimise your unnecessary screen time

Difficult, but simply pressing pause on scrolling, and looking away is the first advice that doctors give. They tell parents to tell to put an alarm on the kids’ mobile screen and restrict them to use it in particular periods of time.

Use ‘night mode’ on your screens

If you’re so busy working that you have to use digital devices, you can shift it into the night mode.

Stop looking at screens for at least one hour before sleep

Set a limit of turning off your devices at least one hour before bedtime and charge your devices in a different room so you are not tempted to turn them back on.

Use an anti-glare coating on your glasses and screens

Anti-reflective coating basically works with the principle of destructive interference. It not only helps you in front of a screen, but also helps you when you’re driving for example, by reducing the glare from headlights. Using matte screens can also reduce glare, increase contrast and reduce eye strain.

Blink, blink, blink

One reason that we are more susceptible to dry eye when using electronics is that our blink rate is reduced significantly. Put a sticky note on your computer screen that says 'Blink!', as blinking more often will keep your eyes moist and refreshed.

Sit at an arm’s length from your screen

You have to position yourself 25 inches or an arm's length away and preferably the screen should be a little lower so that your gaze is shifted downwards so that your eye doesn't become dry because your cornea is less exposed and covered by your lids.