Updated on 

November 17, 2021

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What Does Blue Light Do to Your Eyes?

Key Takeaways 

  • Most blue light exposure is from the sun. However, some health experts are concerned that artificial blue light may be damaging to your eyes. 
  • Blue light damages cells in laboratory animals. But there is not much research that suggests blue light from LED screens damages human eyes.
  • Consistent exposure to artificial blue light may possibly contribute to digital eye strain. It’s best to take frequent breaks from screen time.
  • Blue light can also affect your body’s ‘sleep-wake’ cycle. This is why it’s recommended to reduce exposure before bed (or use amber-light mode).

What is Blue Light?

Blue light is part of the visible light spectrum. This is what the human eye can see.

Blue light vibrates within the 380 to 500-nanometer range. It has the shortest wavelength and the highest energy of visible light.1 

Around one-third of visible light is considered high-energy visible or blue light. Sunlight is the most significant source of blue light. 

Artificial sources of blue light include:

  • Fluorescent light
  • Compact fluorescent light (CFL) bulbs
  • LEDs
  • LED televisions
  • Computer screens
  • Smartphones
  • Tablet screens

What Devices Produce Blue Light? 

Blue light is all around us. 

Today, people are exposed to more blue light than ever. This is due to the widespread use of devices with light-emitting diode (LED) technology.

The following devices produce high amounts of blue light:

  • Laptop and computer screens
  • Flat-screen televisions
  • Cell phones
  • Tablets 

How Does Blue Light Affect Your Eyes? 

Your eyes can protect themselves from some kinds of light. 

For example, your cornea and lens protect the light-sensitive retina from UV rays. Your retina is located at the back of your eye.

However, your eyes cannot protect themselves from blue light exposure. The natural blue light from the sun exceeds the amount emitted from a device.

Some eye health experts are concerned about the blue light emitted from digital devices. This is because many people spend so much time using them closely. 

A 2020 study found that during COVID-19 lockdowns, 32.4 percent of the participants used a blue-light-emitting device nine to eleven hours a day.2

Another 15.5 percent used devices 12 to 14 hours a day. This significant amount of time using screens is likely due to the way people lived and worked during the pandemic.

Research does not currently appear to validate the concern about exposure to blue light. Eye doctors state there is little proof that blue light exposure from digital devices damages the retina.4 

However, there is one recent exception. Doctors reported that a woman using an LED face mask to improve her skin suffered from distorted vision and a retinal lesion afterward.8

Additionally, some animal studies show that blue light exposure can damage retina cells.3

LED devices are still relatively new. No long-term studies have shown how blue light may affect your eyes during your lifetime.8

Risks of Blue Light on Eye Health 

Current research suggests that blue light exposure from devices likely doesn’t pose a serious risk to your eyes. 

However, there are still some risks to consider:

1. Age-related macular degeneration (AMD)

AMD is the leading cause of sight loss in people over 50. It occurs when a structure in the back of your eye becomes damaged as you age. This structure is called the macula

AMD causes vision loss in the center of your field of vision. Details and objects in the middle of your sightlines become blurry. Over time, they may become impossible to see.

Animal and lab studies have raised questions about whether blue light can speed up AMD. 

But researchers don’t believe there is a link between using LED digital device screens and AMD.4

2. Digital eye strain

Using digital screens up close or for long periods can cause eye strain.6

When people use digital devices, they tend to blink less often than usual. Fewer blinks mean less moisture and more strain on the eyes.

Digital eye strain symptoms vary. 

You may notice:

  • Eye dryness
  • Sore or irritated eyes
  • Tired eyes
  • Headaches
  • Facial muscles fatigued by squinting

3. Poor sleep quality

Blue light exposure may affect your sleep-wake cycle. 

Light sensors in your eyes and skin can tell the difference between daylight and nighttime. 

Bright daylight has intense blue waves. Warmer, redder tones indicate that the day is ending.

When the light around you settles into sunset shades, the sensors in your eyes trigger your body to release its natural stores of melatonin. Melatonin is a sleep-inducing hormone.

When you experience blue light exposure in the evening hours, your body does not release as much melatonin as usual. As a result, your sleep cycle is delayed or disrupted.7

4. Other risks

Other problems may develop from harmful blue light, including:

  • An increased risk of hormone-related cancers. For example, breast and prostate cancers10
  • Lower levels of leptin. This is a chemical that signals fullness following meals11
  • Metabolic changes. Especially blood sugar levels

How to Protect Your Eyes From Blue Light 

The following steps may help reduce the risks from exposure to blue light:

1. Take frequent breaks 

When using a device that emits blue light, stop every 20 minutes. Try focusing on objects that are around 20 feet away. Study those objects for 20 seconds before returning to screen time.

2. Keep your eyes moist 

Eye drops and room humidifiers can help keep your eyes from becoming too dry and irritated while using devices.

3. Use prescription eyeglasses

Squinting at screens for extended periods is not healthy for your eyes. 

If you need prescription eyeglasses to correct your vision, make sure you wear the right prescription suitable for the distance between your eyes and the screen. This is ideally arm’s length away. Most glasses are designed for longer distances.

4. Adjust the blue light on your screen 

To lessen the risk of eye strain and sleep issues, try setting your screens to a night shift setting. The night shift setting typically uses warmer tones. 

5. Try blue light screen filters 

You can buy blue light filters such as screens for your computer screen when working at night. These filters can reduce the glare from your screen.12 

Blue light filtering screens can block blue light by up to 30 to 60 percent. However, it’s not clear if blocking blue light helps improve the sleep-wake cycle for those who use back-lit screens before bed.

6. Use blue light glasses 

Blue light blocking glasses contain lenses designed to reduce the blue light that reaches the eyes. 

These lenses filter blue light rays to help stop them from entering your eyes and damaging them. Blue light lenses usually have a slightly yellow tint to counterbalance blue light.

12 Cited Research Articles
  1. Is blue light from your cell phone, TV bad for your health?, UC Davis Health, May 2019
  2. Bahkir, Fayiqa Ahamed, and Srinivasan Subramanian Grandee. “Impact of the COVID-19 lockdown on digital device-related ocular health.” Indian journal of ophthalmology vol. 68,11 (2020): 2378-2383
  3. Chen, Pei et al. “Retinal Neuron Is More Sensitive to Blue Light-Induced Damage than Glia Cell Due to DNA Double-Strand Breaks.” Cells vol. 8,1 68. 18 Jan. 2019
  4. Blue-light hype or much ado about nothing?, American Optometric Association, July 2019
  5. Digital Devices and Your Eyes, American Academy of Ophthalmology, December 2020
  6. Jaiswal, Sukanya et al. “Ocular and visual discomfort associated with smartphones, tablets and computers: what we do and do not know.” Clinical & experimental optometry vol. 102,5 (2019): 463-477
  7. Chang, Anne-Marie & Aeschbach, Daniel & Duffy, Jeanne & Czeisler, Charles. (2014). Evening use of light-emitting eReaders negatively affects sleep, circadian timing, and next-morning alertness. Proceedings of the National Academy of Sciences of the United States of America. 112
  8. Kim, Tae Gi et al. “Photochemical Retinopathy induced by blue light emitted from a light-emitting diode Face Mask: A case report and literature review.” Medicine vol. 99,24 (2020)
  9. Tosini, Gianluca et al. “Effects of blue light on the circadian system and eye physiology.” Molecular vision vol. 22 61-72. 24 Jan. 2016
  10. Garcia-Saenz, Ariadna et al. “Evaluating the Association between Artificial Light-at-Night Exposure and Breast and Prostate Cancer Risk in Spain (MCC-Spain Study).” Environmental health perspectives vol. 126,4 047011. 23 Apr. 2018
  11. Driller, Matthew William et al. “Hunger hormone and sleep responses to the built-in blue-light filter on an electronic device: a pilot study.” Sleep science (Sao Paulo, Brazil) vol. 12,3 (2019): 171-177
  12. Smith, Andrew K et al. “The Effect of a Screen Protector on Blue Light Intensity Emitted from Different Hand-held Devices.” Middle East African journal of ophthalmology vol. 27,3 177-181. 30 Oct. 2020
Melody Huang is an optometrist and freelance health writer. Through her writing, Dr. Huang enjoys educating patients on how to lead healthier and happier lives. She also has an interest in Eastern medicine practices and learning about integrative medicine. When she’s not working, Dr. Huang loves reviewing new skin care products, trying interesting food recipes, or hanging with her adopted cats.
Ellie Swain earned her B.A. in Sociology from the University of Sussex in the United Kingdom. After working in digital marketing and copywriting after graduating, she transitioned to full-time freelance writing and editing. Ellie has a passion for social causes and writes regularly on issues of homelessness in which physical and mental health disorders are common among rough sleepers. She aims to create authoritative and research-backed content on addiction to encourage people to find the support and treatment they need.
https://www.visioncenter.org/author/ellie/
Author: Ellie Swain  | UPDATED November 17, 2021
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Medical reviewer: Dr. Melody Huang, O.D.
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Dr. Melody Huang, O.D.
The information provided on VisionCenter.org should not be used in place of actual information provided by a doctor or a specialist.

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