Knowledge Zone

Blue light: what is it and how to protect your eyesight from it?

Are you already familiar with the concept of blue light? It is high-energy visible light emitted by the sun, but also by the devices we use every dayThey are emitted by smartphones, laptops, tablets, televisions that we use for work and entertainmentFrom our article you will not only learn what blue light is, but also how and why you should protect your eyes from itWe have also collected interesting facts about blue light that are sure to interest you and expand your knowledge.

1. 1. What is blue light?
2. 2. How and why should you protect your eyes from it?
3. 3. Interesting facts about blue light.
4. 4. Research and publications.

What is blue light?

Blue light is the most energetic part of the spectrum of visible radiation: these are electromagnetic waves with a wavelength of 380-500 nm - our eye perceives them as light of violet and blue color.

Wavelength vsradiation energy - blue light is only slightly less energetic than UV radiation

Along with the sun's rays, natural blue light reaches the Earth's surface - in the morning it helps synchronize our biological clocks with the daily rhythm of activityIn addition to natural blue light, our eyes are in contact with artificial blue light emitted by smartphones, monitors, LED lighting, among others.

Monitor glasses help protect eyesight from blue light

How does blue light affect vision and how to protect yourself?

The current state of knowledge and research shows that it is worth protecting the eyes from blue light, because overexposure has a negative impact on our vision, as well as on our healthDue to the duration of action, we can divide the effects of blue light on our body into two types: short-term and long-term.

Matting and yellowing of the lens of an elderly person's eye causes less blue light to reach it than in a child.

In order to protect our body from the harmful effects of blue light, it is of course advisable to limit our eyes' exposure to electronic devicesHowever, it is impossible to eliminate them, as they serve us for work, study and entertainmentWhen using a computer, smartphone or TV, it's a good idea to put on computer glasses that will help reduce the access of blue light to our eyes.

Interesting facts about blue light - did you know that?

We already know what blue light is, and the danger it poses to our healthWe have also collected 5 facts about blue light that will help you expand your knowledge in this area.

1Disturbed circadian rhythms and reduced sleep time have been described as risk factors for astronauts and NASA ground control workers.

2People with lighter eyes (blue, green, gray) are more vulnerable to the harmful effects of blue light because they have less melanin, which has a protective function against UV radiation, among other thingsLess melanin means less natural protection against the potential harmful effects of intense light, including blue light.

3atmospheric particles scatter sunlight in all directions; the shorter the wavelength (closer to blue and violet), the more it is scatteredWhen we look at the sky illuminated by the sun's rays during the day (not the sun's disk), what reaches us are the scattered rays - that is, mainly blue rays (light).

4even on a cloudy day, significant amounts of UV rays and blue light reach the surface of the earth (you can check this yourself in a simple way: with our Real Shades Switch glasses, which change color under the influence of UV rays).

5 The lens in our eyes yellows at a rate of about 0.6% per year, making it better and better at filtering out blue light over timeAdult eyes are less susceptible to the harmful effects of blue light than children's eyes.

Research and publications

1. Effects of blue light on melatonin secretion:
   "Effects of Filtering Visual Short Wavelengths During Nocturnal Shiftwork on Sleep and Performance."
   https://pubmed.ncbi.nlm.nih.gov/23834705/
   publication: July 2013
   Brief:
   A study conducted at the University of Toronto found that people wearing glasses with a blue light filter produced more melatonin than those not wearing such glasses.
2. Effect of blue light on melatonin secretion #2:
   "Blue light from light-emitting diodes elicits a dose-dependent suppression of melatonin in humans".
   published December 2010
   https://pubmed.ncbi.nlm.nih.gov/21164152/
   Brief:
   Light, and blue light in particular, suppresses melatonin secretion in humans.
   Blue monochromatic light increases alertness and arousal more than longer-wavelength light.
3. Discoveries and therapies in phototoxic retinal damage:
   "New discoveries and therapies in retinal photoxicity".
   published: spring 2013
   https://www.researchgate.net/publication/275552786_NEW_DISCOVERIES_AND_THERAPIES_IN_RETINAL_PHOTOTOXICITY
   Abbreviation:
   Blue light, due to its high energy, induces and accelerates photochemical reactions and produces free radicals that damage cellsThe harmfulness of blue light in the outer cells of the retina manifests itself in the photoreceptors and in the retinal pigment epithelium.
4. Opinion on the harmfulness of blue light emitted by LEDs:
   "OPINION of the French Agency for Food, Environmental and Occupational Health & Safety".
   Publication: April 2019
   https://www.anses.fr/en/system/files/AP2014SA0253EN.pdf
   Brief:
   Evidence has been presented that the blue light emitted by LEDs has phototoxic effectsThe negative effects on the body are particularly related to the organ of vision and can lead to irreversible destruction of retinal cells.
5. Blue light phototoxicity to human corneal and conjunctival epithelial cells:
   "Blue light phototoxicity toward human corneal and conjunctival epithelial cells in basal and hyperosmolar conditions".
   publication: July 2018
   https://www.sciencedirect.com/science/article/abs/pii/S0891584918312541
   Abbreviation:
   Corneal and conjunctival epithelial cells were most affected by violet-blue light, but also longer-wavelength blue lightExposure to blue wavelength bands significantly reduced cell viability, affected cell morphology and induced overproduction of reactive oxygen species (ROS).
6. Research progress about the effect of blue light on the eyes:
   "Research progress about the effect and prevention of blue light on eyes".
   publication: December 2018
   https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6288536/
   Brief:
   Effects on the cornea - blue light increases the production of reactive oxygen species in corneal epithelial cells, oxidative damage occurs that can lead to ocular inflammation and xerophthalmia (dry eye syndrome).
   Effects on the lens - blue light can lead to the development of cataracts.
   Effects on the retina - blue light can accelerate the onset of AMD (age-related macular degeneration).
7. Phototoxicity and blue light protection
   "Protective effects of blue light-blocking shades on phototoxicity in human ocular surface cells"
   published May 2019
   https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6557184/
   Abbreviation:
   Blue light damages ocular surface cells, it is recommended to protect against blue light to maintain eye health.