Eye specialist Dr Claudine Pang shares what you need to know to protect your precious vision – and that of your little ones.
In today’s world where people are often glued to their devices for long hours daily, there are increasing concerns about the health implications of excessive screen time, and, in particular, blue light exposure. Is blue light really bad for your eyes, and what can you do if banishing the screens from your life is not an option? Here, an eye health expert weighs in.
Prolonged screen time can lead to digital eye strain. Ever since the Covid-19 lockdown and with more people working on their computers, I have seen a significant increase in the number of young patients with digital eye strain symptoms such as eye fatigue, eye pain, difficulty in focusing, blurring of vision, and headaches.
You may also have read that too much screen time can cause myopia or short-sightedness. Prolonged screen time equates to prolonged near work, which stimulates the eye to become myopic, or short-sighted.
High myopia (a spectacle degree of 600 and above) is especially worrying as it increases the risk of multiple eye problems later in life such as retinal tears, retinal detachment, myopic macular degeneration, macular schisis, macular holes, epiretinal membranes, glaucoma, and early cataract formation.
No, blue light from digital screens does not play a part in myopia progression. It is the nature of the excessive near work that leads to myopia progression, and not the blue light itself. In fact, natural blue light from the sun is needed to prevent the progression of myopia, although the mechanisms (how) are not well understood at the moment. Studies show that children who engage in outdoor play for 10 to 14 hours a week had a lower rate of myopia progression.
Blue light is one of the colours in the visible light spectrum that can be seen by human eyes. Blue light is a shorter wavelength on the spectrum, which means it produces higher amounts of energy. There is natural blue light from the sun and artificial blue light from electronic devices, digital screens, as well as LED and fluorescent lighting.
Natural blue light is needed by the human body to help regulate its normal circadian rhythm. Excessive blue light exposure may adversely affect our sleep/wake cycles. WE also need natural blue light to elevate our mood and increase our overall sense of well-being, so deprivation of blue light may lead to depression.
The truth is that no one knows exactly how blue light can affect human eyes – yet. There have been no documented studies in humans to show that blue light causes direct damage to the eyes.
Since UV damage leads to cataract formation, some scientists think that blue light may lead to cataract formation as well, although this has not been well studied or proven. Animal studies have shown that excessive blue light can lead to cellular damage in mouse and rabbit retina. Hence, it is extrapolated that excessive blue light may affect the human retina, too.
The levels of blue light from consumer electronics is low and unlikely to lead to human retina damage, if used in moderation. However, if electronic devices are used in excess for prolonged periods, it remains unknown as to whether there will be any adverse effects on the human eye.
The most conclusive consequence of prolonged exposure to blue light is that it affects the normal secretion of the hormone melatonin at night, and disrupts our sleep cycle. This is why we should reduce the use of electronic devices especially at night, for better sleep.
Based on animal data that show possible damage to mouse and rabbit retina, I personally prefer to err on the side of caution and encourage limiting excessive blue light exposure to our eyes.
At the same time, it is unscientific to equate all blue light as harmful. We all need some blue light to regulate normal circadian rhythms and prevent the development of myopia. Research has also associated blue-light deprivation with depression-like changes in the brain. As with most things in life, blue light exposure should be kept within moderate amounts.
Most normal digital displays present minimal risks as the blue light emittance is within standard acceptable range. However, this is only a conclusion with respect to short-term exposure. If long-term exposure is necessary, additional anti-blue light measures would be encouraged.
Blue light filtering eyewear are not medical devices, and are not regulated in Singapore. Depending on its quality, such lenses may filter between 20% and 90% of blue light. Since blue light filtering lenses are not regulated, often times, they may not filter as much blue light as advertised. Only a blue light spectrometer will be able to measure the amount of blue light filtering accurately.
Blue light lenses may be helpful in reducing the amount of blue light exposure, especially for people who are getting prolonged exposure to digital screens. It is less critical for people who have little to moderate exposure to digital screens. As mentioned before, we do need a certain amount of blue light for health reasons so we should not aim to filter out 100% of blue light.
I would not recommend blue light filtering eyewear in children since natural blue light is needed for the normal growth of the eyeball, and for myopia prevention. However, concerned parents can consider placing blue light filtering films directly in front of digital screens to filter blue light coming from the electronic device.
In adults who use electronic devices excessively, it may be helpful to use blue light filtering lenses or films placed in front of the device to reduce the amount of blue light they are getting.
What are your recommendations for adults and children who are concerned about prolonged screen time, to keep their eyes healthy and protect their vision?
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This feature article is produced in consultation with Dr Claudine Pang from Asia Retina Eye Surgery Centre. Artwork by Curatedition, all rights reserved.
All content featured in Curatedition Health and Wellness articles is for informational purposes only and not intended to be a substitute for personalised professional medical advice, diagnosis, or treatment. If you think you have a medical emergency, call your doctor, qualified health service provider, or 995 immediately.