By: Alexis O’Neil
Blue light has become a hot topic in eye health, especially with the increased use of digital devices. Many people worry about its effects on vision, digital eye strain, and sleep. This post will break down common myths and facts about blue light and how it impacts our eyes.
What is Blue Light?
Blue light is part of the visible light spectrum, with wavelengths between 380-500 nanometers.1 Blue light is mostly emitted by the sun as an essential part of our environment; however, it is also emitted artificially by LED lights, smartphones, tablets, and computer screens.1
What are Blue Light Blocking Lenses?
Blue light blocking lenses can come in the form of eyeglasses, contact lenses, or intraocular lenses that are implanted during cataract surgery.1 These lenses contain or are coated with materials that absorb blue light, blocking or attenuating these wavelengths before they reach the back of the eye.2
Myth #1: Blue Light from Screens Causes Eye Damage
Fact: Some studies suggest that excessive exposure to high-energy blue light can cause oxidative stress in retinal cells.1 As such, caution should be used in the presence of high luminance LED lights to prevent direct exposure to the eyes.1 That being said, there is no scientific evidence that blue light from screens permanently damages the retina. The amount of blue light emitted by screens is lower than natural exposure from the sun and far below the international exposure limits, even for prolonged viewing.2 Organizations like the American Academy of Ophthalmology (AAO) state that normal screen use does not lead to retinal damage.1, 3
Myth #2: Blue Light is the Main Cause of Digital Eye Strain
Fact: Digital eye strain can manifest in symptoms such as eye fatigue, strain, blurred vision, irritated or burning eyes, dry eyes, headache, or general discomfort.1 According to the American Optometric Association, digital eye strain is often caused by prolonged screen use, not blue light itself.4 Poor lighting conditions, glare from digital screens, improper viewing distances, poor posture, and prolonged near-focus work all contribute to the discomfort of digital eye strain. Additionally, we simply tend to blink less when looking at screens which can cause dryness and blurred vision.
Myth #3: Blue Light-Blocking Glasses Prevent Eye Strain
Fact: Blue light glasses are marketed as a tool that alleviate these symptom, but there is no consistent evidence in the literature showing their effectiveness.1, 2 As of 2021, the AAO does not recommend blue-light blocking glasses for computer use.3 In fact, some experts argue that blue light blocking lenses can negatively impact contrast sensitivity and colour vision.1, 2
Fact: Blue Light Affects Sleep
One well-supported concern about blue light is its impact on sleep.5 While exposure to blue light during the day is essential for alertness and cognitive performance, low-intensity blue light before bed suppresses melatonin, the hormone that regulates sleep-wake cycles. This can delay sleep onset, disrupt sleep cycles, and reduce sleep quality. To minimize this effect, experts recommend reducing screen time 2-3 hours before bed or using night mode settings.6 The efficacy of blue light glasses on sleep quality has also been debated, with some studies stating that self-reported sleep quality was better with the use of blue-blocking lenses and others reporting no difference in comparison to regular lenses.2
How to Reduce Digital Eye Strain
Instead of focusing solely on blue light, adopt these habits to protect your eyes: 3, 4, 6
Follow the 20-20-20 rule: Every 20 minutes, look 20 feet away for 20 seconds.
Blink frequently to keep eyes moist.
Adjust screen brightness and contrast to comfortable levels.
Maintain proper posture and screen distance (about an arm’s length away).
Use artificial tears if needed to prevent dry eyes.
Conclusion
While blue light does not damage the eyes, it can affect sleep patterns. Digital eye strain is caused more by screen habits than blue light exposure itself. Instead of relying on blue-light-blocking glasses, focus on healthy screen practices to keep your eyes comfortable. By making small changes, you can protect both your vision and your sleep.
References
1. Cougnard-Gregoire A, Merle BMJ, Aslam T, Seddon JM, Aknin I, Klaver CCW, et al. Blue Light Exposure: Ocular Hazards and Prevention—A Narrative Review. Ophthalmology and Therapy. 2023;12(2):755-88.
2. Lawrenson JG, Hull CC, Downie LE. The effect of blue‐light blocking spectacle lenses on visual performance, macular health and the sleep‐wake cycle: a systematic review of the literature. Ophthalmic & physiological optics. 2017;37(6):644-54.
3. Vimont C. Are Blue Light-Blocking Glasses Worth It? American Academy of Ophthalmology2021 [Available from: https://www.aao.org/eye-health/tips-prevention/are-computer-glasses-worth-it.
4. Computer vision syndrome American Optometric Association [Available from: https://www.aoa.org/healthy-eyes/eye-and-vision-conditions/computer-vision-syndrome?sso=y.
5. Wahl S, Engelhardt M, Schaupp P, Lappe C, Ivanov IV. The inner clock—Blue light sets the human rhythm. Journal of Biophotonics. 2019;12(12):e201900102.
6. Vimont C. Should You Be Worried About Blue Light? American Academy of Ophthalmology2021 [Available from: https://www.aao.org/eye-health/tips-prevention/should-you-be-worried-about-blue-light.
Commenti