Mahatabuz Zaman, B.Optom

Optometrist, Sri Sankaradeva Nethralaya, Guwahati


Not so long ago, social connectivity only meant talking over wired telephones or a feature phone with our relatives and friends. Not everyone had the privilege to own a PC or use the internet, and most video calls happened only in an internet café through Skype, with a VGA webcam. But things have changed a lot now.

Over the past decade, smartphones have revolutionized our lives in ways that go well beyond how we communicate. Besides texting, calling and emailing, more than two billion people around the world uses these devices to navigate using GPS maps, book a taxi to ride, order foods online, buy products online, play video games, watch videos on OTT platforms, read news and books, and not least of all, to participate in social media. All these have increased our screen usage time, and thereby increasing the cases of computer vision syndrome. So, when someone goggles their symptoms related to CVS on the internet, sooner or later the algorithms of the social media company ensure that the person sees an online advertisement of blue cut lenses or what we generally call computer glasses. Happened with most of us, right? Snooping and showing us the most relevant ads, that’s online marketing for you. But that is a different topic, I will discuss about the lenses only. According to a survey almost 40% of internet users in India knows about blue cut lenses, thanks to such an aggressive ad campaign by an online specs company. As we know, with awareness, demand increases, so it has really happened. Most people now-a-days asks for blue cut lenses in optical shops, and those who do not ask, the optical salesman tries to lure them into buying the lenses by giving demonstration. What the optical salesman does is, he shines a blue light through the lenses to show that the light does not pass through it. The customer gets impressed and 90% of them ends up buying the lenses. But most of such lenses are made in china, non-branded, generally cheap with high profit-margin for the seller. Even the big online specs company (which should not be named) also sells spectacles with such lenses. So, now you may ask me, which blue cut lenses to buy? My answer would be, not the ones which seems and claims to cut 100% transmission. A good blue cut lens will never stop all the blue light passing through it, during the demonstration. Because not all blue light is bad. Blue light generally ranges from 380-500 nm wavelength and is made up of two parts- the Bad Blue-Violet which ranges from 380-440 nm wavelength and the Good Blue Turquoise which ranges from 450-500 nm. The bad blue light is potentially damaging to our eyes and can cause cataracts, macular degenerations, dry eye, photo retinitis etc.  But the good blue light is beneficial and essential for good health, as it helps in regulating our biological rhythms that influences our sleep-wake cycle, it boosts alertness, helps memory and cognitive function, elevates our moods and also makes us feel productive, energized and healthy. So, when we buy such lenses that blocks the entire 380-500 nm wavelength of light, we are also removing the good aspects of blue light from our life as well, which is not at all good for us. So, while buying blue cut lenses online or from your local optical shop next time, make sure you read the lens specifications and only buy the ones which do not block the good blue-turquoise light. Blue cut lenses from reputed ophthalmic lens manufacturers can be relied upon. As a conclusion, I would like to add that, only using blue cut lenses to stay safe from digital hazards is not enough, we should also limit digital usage in our lives. Life itself is a simulation, let us not make it more digital.


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