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Do You Know The Effect Of Blue Light On Your Eyes?

Written by Dr. Naveeda Adam on Sat, 02 December 2023 — Fact checked by Dr Bright Owusu Prempeh

Key Highlights

  • Blue light exposure from screens is less damaging than that from the sun
  • LEDs emit more blue light
  • Nighttime light exposure maybe linked to diabetes, heart disease and obesity
  • Blue light suppresses melatonin and interferes with the sleep cycle 
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In today’s digital age, where screens are an integral part of our daily lives, concerns about the potential effect of blue light on our eyes have gained prominence. Blue light, a type of visible light with a shorter wavelength and higher energy, is emitted by various sources, including smartphones, computers, tablets, and LED lighting.

However, amidst the hype and confusion, it's essential to distinguish between myths and facts regarding the effects of blue light on eye health. In this article, we delve into the science behind blue light, debunk common misconceptions, and unveil the real facts that can help you make informed decisions about protecting your eyes in the digital era.

What is blue light?

With a wavelength between 380 and 500 nanometers, blue light is a type of visible light (nm). This kind of light is perceived as being blue in colour, as the name suggests. Blue light, however, can exist even when it appears to be white or another colour.

This is because blue light has more energy per photon of light than other colours in the visible spectrum, such as green or red light. Blue light is more likely to harm different body cells when absorbed at high enough doses.

What are the different sources of blue light?

What are the different sources of blue light?

Blue light is found in the atmosphere, especially during daytime and has a short wavelength. It is also emitted from light emitting diodes (LED) lighting, compact fluorescent lamps, and all electronic devices with LED displays. Like sunlight, most artificial light sources emit a wide spectrum of light. However, LED's generate deliberately designed relatively narrow light peaks. As a result LED light can be perceived as being nearly identical to white light, or daylight.

In contrast to conventional light sources, white LEDs may actually emit more blue light. LED technology is used to power screens in modern electronics. Typical screens consist of closely spaced, individually controlled red, green, and blue LEDs that produce full colour. However, the majority of blue light is produced by the bright white-light LEDs used to backlight the displays of smartphones, tablets, and laptop computers.

How does blue light affect your health?

Digital blue light is the term used to describe the blue light that electronic devices (e-devices) like smartphones, tablets, and laptops emit when they have LED display screens. Users of all ages are spending exponentially more time on screens. Due to this exposure, there are now worries that vision and eye safety could be compromised. Blue light is also suspected to impact sleep patterns.

How does blue light affect your eyes?

Intense blue light can be harmful to the eyes. Blue light sources in the workplace are intentionally filtered or shielded to safeguard users. However, because many high-power consumer LEDs are so bright (e.g. military grade flashlights), it might be dangerous to stare at them directly.

It has been demonstrated by few studies that blue light increases the production of reactive oxygen species (ROS) in corneal epithelial cells, causing oxidative damage and ocular inflammation. It may also play a role in the development of cataract in the eyes.

However, due to the amount of light they emit, consumer electronics are not damaging to the retina. For instance, the maximum brightness of recent phones is about 625 candelas per square metre (cd/m2), almost 1/10th of the illumination from the Sun.

The risk of macular degeneration or blindness from exposure to typical levels of blue light from consumer electronics is negligible in comparison to the risk from ageing, smoking, cardiovascular disease, high blood pressure, and being overweight.

How does blue light affect your sleep?

How does blue light affect your sleep?

Blue light can interfere with your sleep and possibly lead to disease. Light disrupts the circadian rhythm, the body's biological clock and natural wake and sleep cycle, at night. Studies have linked diabetes, heart disease, and obesity to nighttime light exposure, such as that experienced when working the night shift.

A hormone that affects circadian rhythms, melatonin, is secreted less when one is exposed to light. Even low levels of light can disrupt a person's melatonin production and circadian rhythm. Any type of light can prevent the release of melatonin, but blue light during the night does so more effectively.

Debunking blue light myths

1. Myth 1

Blue light is always harmful - Blue light sources maybe natural or artificial. When compared to Sun exposure, blue light exposure from screens is significantly lower and less damaging.

2. Myth 2

Blue light from digital devices directly damages the eyes - There isn't much scientific proof that blue light from digital devices harms your eyes. The risk of developing macular degeneration or going blind from exposure to typical levels of blue light from consumer electronics is extremely low.

3. Myth 3

Blue light filters eliminate all risks - It is claimed that blue light emitted from digital screens is blocked or filtered out by blue light-blocking glasses with specially designed lenses. Unexpectedly, a lot of the eye problems brought on by digital screens aren't caused by blue light but rather by digital eye strain, which is brought on by staring at screens for extended periods of time, not blinking frequently, and viewing the screens closely. There is lack of evidence that such glasses are effective. No specific blue light-blocking eyewear for computer use is advised by the American Academy of Ophthalmology.

Finding blue light facts

1. Fact 1

Blue light has its set of benefits - Blue light strengthens and stimulates connections between brain areas that process emotion and language, which may help people cope with emotional challenges and regulate their mood over time. Blue light reduces physiological arousal and can be used to induce sleep because it causes a significant decrease in both breath rate and diastolic blood pressure during exposure.

2. Fact 2

Blue light prevents you from falling asleep - Blue light suppresses melatonin (sleep hormone) and affects the body’s biological clock, making it hard to sleep. Excessive blue light at night can stimulate the brain, increase corticosteroid production, thereby affecting sleep quality.

Conclusion

In recent years, the rise in blue light exposure has become a cause for concern, as it poses significant threats to our overall health and well-being.

The abundance of electronic devices and energy-efficient lighting has contributed to the increased prevalence of blue light in our daily lives. One of the most notable negative impacts of prolonged blue light exposure is its effect on our sleep quality. The blue light emitted by screens can disrupt our natural sleep-wake cycle, making it harder to fall asleep and reducing the overall quality of our rest.

Blue light is vital in our modern lives, but understanding its effects on eye health is crucial. Myths persist, but evidence points to concerns about digital eye strain and sleep disruption. By discerning fact from fiction, adopting healthy screen habits, and taking protective measures, navigate the digital realm while safeguarding your eyes. Moderation, awareness, and a holistic approach to eye health are vital in the age of screens and the effect of blue light on our eyes.

Frequently Asked Questions

Blue light from screens can contribute to digital eye strain and disrupt sleep patterns. While it's not directly responsible for permanent eye damage, prolonged exposure can lead to discomfort and sleep disturbances.

Natural blue light from sunlight is essential for regulating our sleep-wake cycle. The concern arises from prolonged exposure to artificial blue light emitted by digital devices, which can lead to eye train and interfere with sleep patterns. 

There is currently no scientific evidence supporting the claim that blue light exposure from screens causes permanent vision loss or eye diseases like macular degeneration. However, it's important to take measures to reduce digital eye strain and protect eye health. 

You can reduce blue light's impact by using blue light filters on devices, adjusting screen brightness, practicing the 20-20-20 rule (taking breaks every 20 minutes), and limiting screen time before bedtime. These measures can help alleviate digital eye strain and improve sleep quality. 

Blue light exposure is a concern for people of all age groups, particularly those who spend extended periods in front of screens. Children, teens, and adults can all experience digital eye strain and disrupted sleep patterns from excessive screen time. It's important to practice healthy screen habits regardless of age.

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Dr. Naveeda Adam

Dr Naveeda Adam is currently Medical Officer of the Gastrology Department at the Muhimbili National Hospital, Dar es Salam, Tanzania.

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4 Comments

  1. Dr. Yin Kyi

    Thu, 02 November 2023, 5 months ago

    Informative and updates about eye health

    Reply
    • Dr. Yin Kyi

      Fri, 27 October 2023, 6 months ago

      Informative and updated information about the blue light’s effects on public health. Hypotheses and explanations are kind of good health education for the public. Congratulations for your interesting and insightful article.

      Reply
      • DR NU WAH WAH TIN

        Tue, 26 September 2023, 7 months ago

        Thanks for your care 🙏Got the valuable information and well noted ☺️May God bless you all, Mega team😃

        Reply
        • Team Good Health By Yourself

          Thu, 28 September 2023, 6 months ago

          Thank you, we are glad you find the information in the blog useful.

          Reply
        • Olapeju Odetoyinbo

          Tue, 26 September 2023, 7 months ago

          This information is a great article, well done.

          Reply
          • Team Good Health By Yourself

            Thu, 28 September 2023, 6 months ago

            Thank you. Happy to hear you find the information useful.

            Reply

          Leave a Comment

          1. Will blue light from electronic devices increase my risk of macular degeneration and blindness?  
          2. Blue light has a dark side  
          3. Munsamy AJ, et al. Evidence on the effects of digital blue light on the eye: A scoping review. African Vision and Eye Health. 2022 May 31;81(1):9.
          4. Zhao ZC, et al. Research progress about the effect and prevention of blue light on eyes. International journal of ophthalmology. 2018;11(12):1999.
          5. Should You Be Worried About Blue Light?  
          6. Do Blue Light Glasses Work?  
          7. Gomes CC, et al. Blue light: A blessing or a curse?. Procedia Manufacturing. 2015 Jan 1;3:4472-9. 

          Our team of experts frequently monitors developments in the health and wellness field, and we update our articles when new information becomes available.

          Current Version

          Dec, 02 2023

          Written By

          Dr. Naveeda Adam

          Fact checked By

          Dr Bright Owusu Prempeh