Blue Light Research
Eyesafe is committed to developing standards and solutions regarding potential risk from blue light. Below is key research that helps guide our decisions and product development.
KEY STUDIES:
1. Phototoxic Action Spectrum on a Retinal Pigment
2. Photoprotective Effects of Blue Light Absorbing Filter Against LED Light Exposure
3. Effects of Blue Light on the Circadian System and Eye Physiology
4. LED for Domestic Lighting: Any Risks for the Eye?
5. White LEDs at Domestic Lighting Levels and Retinal Injury in a Rat Model
KEY EXCERPTS:
Healthy Levels and Ranges of Blue Light and Sunlight
1. “Blue light can be divided into two bands: blue-violet light (415-455 nm) and blue-turquoise light (465-495 nm). When light in the blue- violet range hits the eye, a process unique to this band of wavelength occurs. Not all blue light is harmful; in fact the two bands of blue light mentioned above, blue-violet and blue-turquoise, exhibit vastly different effects on the eyes. Besides helping with visual acuity, contrast acuity, and color vision, blue-turquoise light is essential for our pupillary reflex and for synchronization of our circadian rhythms, which in turn help to maintain and regulate memory, mood, and hormonal balance.” Understanding Blue Light, Retina Today.
2. “One of the benefits of blue light is that it helps to regulate our sleeping pattern because its presence suppresses melatonin production, which makes our bodies ready for sleep.” Balancing the Blues, 20/20 Magazine
3. “Natural blue light reminds our body that it’s daytime, helping boost alertness, heighten reaction times and elevate moods.” Balancing the Blues, 20/20 Magazine
4. “Filters in our narrow bandwidth would not occlude light in the 460–500 nm range, not only essential for color vision but also for pupil constriction and circadian rhythm regulation, both mediated by melanopsin-sensitive retinal ganglion cells.” Phototoxic Action Spectrum on a Retinal Pigment Epithelium Model of Age-Related Macular Degeneration Exposed to Sunlight Normalized Conditions, PLOS one
Children Under 18
1. “The absorption spectrum of the lens changes with age. In young children, more than 65% of blue light is transmitted to the retina. At around 25 years, only 20% of the light between 400 and 460 nm and 50% of wavelengths between 400 and 500 nm are transmitted. With increasing age, the yellow filters of the lens increase and absorb most of the blue light.” Light-emitting diodes (LED) for domestic lighting: any risks for the eye, Progress in Retinal and Eye Research; Behar-Cohen
2. “ANSES recommends that consumer information about health risks related to the use of LED lighting systems be made available immediately pending the implementation of an appropriate regulatory framework. ANSES recommends; 1) To avoid the use of light sources emitting cold-white light (light with a strong blue component) in places frequented by children or in the objects they use (toys, electronic display panels, etc); 2) To ensure that manufacturers and integrators of LEDs carry out quality controls and qualify their products with regard to different risk groups; 3) To setup a clear, easy to understand labeling system for consumers, with a mandatory indication of the photobiological safety Risk Group on the packaging for all types of lighting.” Light-emitting diodes (LED) for domestic lighting: any risks for the eye, Progress in Retinal and Eye Research; Behar-Cohen
3. “Children under 18 are at higher risk for retinal damage from blue light since their young crystalline lenses are clear and do not impede the passage of blue light.”Balancing the Blues, 20/20 Magazine
4. “Recent research found that filtering blue light from LED screens before bed of teenagers significantly weakened the LED-induced melatonin suppression and decreased alertness brought on by blue light before bedtime.” Blue blocker glasses as a countermeasure for alerting affects of evening light-emitting diode screen exposure in male teenagers, The Journal of Adolescent Health
5. “Higher levels of total time spent outdoors, rather than sport per se, were associated with less myopia and a more hyperopic mean refraction, after adjusting for near work, parental myopia, and ethnicity.” Outdoor activity reduces the prevalence of myopia in children, Ophthalmology
Blink Rate, Distance and Eye Strain
1. “The mean distance from the screen was 13.3 inches for smartphone use and 15.6 inches for tablet use. The smaller the screen, the closer the distance of use.” Theme Digital Vision, International Review of Ophthalmic Optics
2. “Blue wavelengths flicker more easily than longer wavelengths, creating a glare that can reduce visual contrast and clarity, leading to eyestrain, headaches, and fatigue.”Balancing the Blues, 20/20 Magazine
Night Time Use of Digital Devices
1. “This more precise and narrower phototoxic action spectrum could be advantageously valued in selective photoprotection ophthalmic filters which would limit the disruption of color vision and of non-visual functions, by contrast to current blue filtering intraocular lenses. Indeed, filters in our narrow bandwidth would not occlude light in the 460–500 nm range, not only essential for color vision but also for pupil constriction and circadian rhythm regulation, both mediated by melanopsin-sensitive retinal ganglion cells.” Phototoxic Action Spectrum on a Retinal Pigment Epithelium Model of Age-Related Macular Degeneration Exposed to Sunlight Normalized Conditions, PLOS one
2. “Use of eReaders prior to bedtime negatively impact sleep, circadian rhythm timing and next morning alertness.” Evening use of light-emitting eReaders negatively affects sleep, circadian timing, and next-morning alertness, PNAS
3. “Melatonin levels studied among those using digital devices 2 hours before bed with and without blue light filtering. Overnight melatonin significantly higher after using blue light filter, than group with no filter.” Protective effect of blue-light shield eyewear for adults against light pollution from self-luminous devices used at night, The Journal of Biological and Medical Rhythm Research
4. “The severity of light-induced retinal damage changes with the time of day with more susceptibility to light damage at night than during the day.” Effects of blue light on the circadian system and eye physiology, Molecular Vision
5. “But not all colors of light have the same effect. Blue wavelengths—which are beneficial during daylight hours because they boost attention, reaction times, and mood—seem to be the most disruptive at night.” Blue light has a dark side, Harvard Medical School
Cumulative Effect, Time Relationship and Photoxicity
1. “Because light has a cumulative effect and many different characteristics (e.g., wavelength, intensity, duration of the exposure, time of day), it is important to consider the spectral output of the light source to minimize the danger that may be associated with blue light exposure. Thus, LEDs with an emission peak of around 470–480 nm should be preferred to LEDs that have an emission peak below 450 nm.”Effects of blue light on the circadian system and eye physiology, Molecular Vision
2. “We thus demonstrated a cell viability loss at all tested wavelengths but with greater and more statistically significant differences under four 10 nm illumination bands centered at 420, 430, 440 and 450 nm. Cell apoptosis was also significantly increased under the same four illumination bands at the two highest A2E concentrations (20 µM and 40 µM). These results suggest that the 415–455 nm spectral range may be the most damaging light for patients at risk for ARMD.”Phototoxic Action Spectrum on a Retinal Pigment Epithelium Model of Age-Related Macular Degeneration Exposed to Sunlight Normalized Conditions, PLOS one
3. “Our results raise questions about adverse effects on the retina from chronic exposure to LED light compared with other light sources that have less blue light. Thus, we suggest a precautionary approach with regard to the use of blue-rich “white” LEDs for general lighting.” White Light-Emitting Diodes (LEDs) at Domestic Lighting Levels and Retinal Injury in a Rat Model, Environmental Health Perspectives
4. “According to a study published in February 2013, it only takes 30 minutes of low-intensity exposure to blue light-emitting lamps at night to significantly disrupt melatonin production in healthy individuals.” Balancing the Blues, 20/20 Magazine
5. “There are two distinct types of photochemical damage. The first type is associated with short but intense exposure affecting the RPE, and the second is longer but less intense light, affecting the outer segment of the photoreceptors. Short (up to 12 h) exposure to blue light may induce damage in the RPE.” Effects of blue light on the circadian system and eye physiology, Molecular Vision
6. “Single 5 min exposure to light did not induce significant damage in photoreceptor cells, whereas a series of 5 min exposures led to significant photoreceptor damage. Furthermore, the time between exposures affects the cumulative effect of light.” Effects of blue light on the circadian system and eye physiology, Molecular Vision
7. “Research suggests that wavelengths from 400-490nm can induce damage to the retina, leading to RPE damage and eventually photoreceptor death. The use of filters that block blue light may provide some protection against the development of AMD.” Effects of blue light on the circadian system and eye physiology, Molecular Vision
Blue Light Filtering
1. “Our result suggests that filtering light in a narrower band from 415 nm to 455 nm may be sufficient to prevent or limit the disease development or progression. This more precise and narrower phototoxic action spectrum could be advantageously valued in selective photoprotection ophthalmic filters which would limit the disruption of color vision and of non-visual functions, by contrast to current blue filtering intraocular lenses [59]. Indeed, filters in our narrow bandwidth would not occlude light in the 460–500 nm range, not only essential for color vision but also for pupil constriction and circadian rhythm regulation, both mediated by melanopsin-sensitive retinal ganglion cells.” Phototoxic Action Spectrum on a Retinal Pigment Epithelium Model of Age-Related Macular Degeneration Exposed to Sunlight Normalized Conditions, PLOS one
2. “The addition of computer gaming glasses with blue light filtering markedly lessened concussion symptoms in patients.” The Gaming of Concussions: A Unique Intervention in Postconcussion Syndrome, J Athl Train
3. “The present study shows that absorbing filters in the blue region of the spectrum may protect RPE cells from the damaging effects of LED light. The results of this study clearly show that a blue light absorbing filter decreases the apoptotic cellular death by 50-89% and inhibits DNA damage by 57-81%, decreases ROS production and increases mitochondrial membrane potential.” Photoprotective Effects of Blue Light Absorbing Filter against LED Light Exposure on Human Retinal Pigment Epithelial Cells in Vitro, Journal of Carcinogenesis & Mutagenesis
4. “In conclusion, this study has found that the use of a blue light absorbing filter reduces phototoxic damage in human RPE cells exposed to LED light, providing an ocular photoprotector effect. After 3 light-darkness cycles (12 hours/12 hours) exposure to LED light, RPE cells protected by a blue light absorbing filter showed a decrease in apoptotic death accompanied by a decrease in DNA damage and a reduction in ROS levels. Photoprotective Effects of Blue Light Absorbing Filter against LED Light Exposure on Human Retinal Pigment Epithelial Cells in Vitro, Journal of Carcinogenesis & Mutagenesis
5. “Reducing short-wavelength blue light in dry eye patients with unstable tear film improves performance on tests of visual acuity.” Reducing Short-Wavelength Blue Light in Dry Eye Patients with Unstable Tear Film Improves Performance Acuity, PLOS One