Home Health & Wellness Do Blue Light Glasses Work? Here’s What the Experts Say

Do Blue Light Glasses Work? Here’s What the Experts Say

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Is wearing blue-light glasses necessary? Let’s find out. If you want more information about eyeglasses and eye care or want to buy glasses online, check out CheRing, they have the newest collection of clear glasses frames.

What is blue light?

Visible light in natural light can be recognised by the human eye. Red, orange, yellow, green, blue, and violet refer to the visible seven-colour light. Different colours of visible light have different wavelengths. The wavelength of blue light is 400~500 nanometers, which is a short wavelength and has the characteristics of high energy and strong penetrating power. Beyond the visible light range, there are many types of light that are invisible to our naked eyes, such as shorter-wavelength ultraviolet rays and longer-wavelength infrared rays.

25%~30% of sunlight is blue light. The light emitted by electronic devices such as mobile phones, tablets, computer screens, and LED lights that we cannot “cut off” in our lives all contain blue light. Therefore, blue light is everywhere.

Is blue light harmful?

Blue light can be used to treat neonatal jaundice. This is because when newborns develop jaundice, the absorption band of bilirubin deposited in the body is consistent with the blue light band. Through the action of light and oxygen, fat-soluble bilirubin can be converted into water-soluble bilirubin, which is then excreted through the stool.

Blue light also regulates biological rhythms. Mainly blue light of 480~500 nanometers can regulate melatonin levels and is related to people’s sleep, mood, and memory.

An animal experiment conducted by Fudan University on the effects of monochromatic light on the refractive development of guinea pigs found that 430-nanometer blue light can prevent the development of optical defocus myopia in guinea pigs. This means blue light may have a protective effect against myopia. In recent years, many studies have confirmed that the current high incidence of myopia in children is related to a lack of outdoor activities. The blue light in indoor light is not as good as natural light. The lack of blue light may also be a factor leading to the high incidence of myopia.

Children using light sources with a certain proportion of blue light may have a certain delaying effect on the development of myopia. However, the current conclusion that blue light has a protective effect against myopia needs more research to be confirmed.

Therefore, it is not accurate to say that blue light is harmful. What scares people is not so much blue light as it is short-wave blue light.

Can blue light glasses protect our eyes?

Anti-blue light glasses reflect harmful blue light through a coating on the lens surface (i.e., anti-blue light film), or add an anti-blue light factor to the lens base material to absorb harmful blue light, thereby blocking blue light and effectively reducing the impact of blue light on the eyes. In addition, anti-blue light glasses can improve the visual contrast sensitivity of the human eye and improve visual function.

A study shows that after adults wear anti-blue light glasses for a period of time, their visual contrast sensitivity can be improved under different distances, light and shade, and glare environments. For patients undergoing retinal laser photocoagulation for diabetic retinopathy, blue light-blocking glasses can improve visual quality after retinal photocoagulation. People with dry eyes, especially those who use electronic products such as computers, mobile phones, and tablets for a long time, are prone to glare and visual fatigue. After wearing anti-blue light glasses, optimal visual acuity and contrast sensitivity are improved to varying degrees.

From this perspective, anti-blue light glasses can be regarded as a helper to protect your eyes.

Can everyone wear blue light glasses?

Not everyone can wear anti-blue light glasses. People do not need to be overly sensitive to blue light hazards when carrying out normal work and study, nor do they need to wear anti-blue light glasses every day. For people who have retinopathy or have undergone cataract surgery, the filtering effect of glasses on blue light is relatively poor, and they need to pay more attention to preventing blue light than normal people. You can choose to wear anti-blue light glasses. In addition, for people who have been facing electronic screens for a long time, a qualified pair of anti-blue light glasses can help reduce glare and visual fatigue symptoms, and can also reduce the damage of blue light to the eyes to a certain extent.

Although it was mentioned above that blue light may have a certain degree of myopia protection, it is not recommended that children and teenagers wear anti-blue light glasses on a daily basis. Paying attention to eye hygiene is more important than wearing anti-blue light glasses. After all, there are many kinds of habits that harm the eyes, and blue light cannot always be blamed for them. A good eye habit should follow the “20-20-20” principle, that is, use your eyes for 20 minutes, stare at a place 20 metres away, and let your eyes rest for at least 20 seconds.

Children and adolescents need to protect their eyes and do more outdoor activities. More than 2 hours of outdoor activities during the day can help control the progression of myopia. Your true love for your eyes should be reflected in good behaviour and habits. Healthy eye habits can help you have healthy eyes.

More to know: is short-length blue light harmful?

Short-wave blue light is light with a wavelength between 400 and 480 nanometers and relatively high energy. The most common hazards of short-wave blue light are as follows:

  • Sleep disorders. Short-wave blue light inhibits the secretion of melatonin, and reduced melatonin secretion affects sleep status. This is also the reason why many people complain that playing with mobile phones or tablets before going to bed leads to poor sleep quality.
  • Glare and visual fatigue. High-energy short-wave blue light has a high probability of scattering when encountering small particles in the air, which can easily cause glare, causing the image that is originally focused on the retina to focus in front of the retina, causing colour vision deviation. This also explains why people who use mobile phones or computers for long periods of time experience discomfort such as blurred vision and eye soreness.
  • Lens opacity. In addition to ultraviolet rays that cause lens opacity and cataracts, the lens of the eye also absorbs part of the blue light, further aggravating cataracts.
  • Macular degeneration. Short-wavelength blue light between 400 and 450 nanometers will increase the amount of toxins in the macular area, leading to macular degeneration in the fundus.
  • Retinal light damage. Short-wavelength blue light between 400 and 450 nanometers has strong penetrating power and will penetrate the lens and reach the retina. Damage and atrophy of retinal pigment epithelial cells and light-sensitive cells can lead to irreversible decline or even loss of vision.

Final thoughts

The damage of blue light to the retina is related to the degree and time of illumination. In 2014, the Visual Health Laboratory of the China Institute of Standardization and Wenzhou Medical University conducted a blue light retinal damage study and concluded that when blue light has a broad peak spectrum of 460~500 nanometers and an illumination of more than 1500 lux, it directly irradiates retinal cells for more than 3 hours. At this time, there will be a significant decrease in cell viability and apoptosis.

In fact, daily indoor illumination generally does not exceed 600 lux. Many household LED lights are structurally packaged and use backlight or side-emitting modes. The intensity of blue light is far from causing damage.

Our eyes are not that fragile. The human eye has the ability to automatically adjust the light entering the eye, and the lens itself can also filter part of the blue light. Therefore, as long as you do not look directly at particularly strong light, exposure to blue light in daily life is far from dangerous. However, people who use electronic products for long periods of time may suffer from visual fatigue caused by blue light.




David Radar, a psychology graduate from the University of Hertfordshire, has a keen interest in the fields of mental health, wellness, and lifestyle. 

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