There are two very different products being sold under the name 'red light glasses' and they work through completely different mechanisms, with different evidence bases, different use cases, and different levels of scientific support.
The first is blue-light-blocking glasses, amber or orange-tinted lenses worn in the evening to reduce the wavelengths of light that tell your brain it is still daytime.
The second is photobiomodulation devices. These are red and near-infrared light sources used to stimulate cellular energy production in the retina and surrounding tissue.
Lumping them together, as most consumer marketing does, causes real confusion. For people in Northern Hemisphere, where the sun disappears for months, seasonal mood disorders are clinically significant, and screen-saturated modern life is compressing the sleep of an entire generation, understanding exactly what these devices do, and when each is worth using, is not a minor distinction.
Category 1:
Blue-light-blocking glasses (amber/orange lenses) worn in the evening, designed to protect melatonin secretion by filtering the short wavelengths, principally 446–480 nm, that activate the melanopsin-containing photoreceptors responsible for circadian regulation. [1]
Category 2:
Photobiomodulation (PBM) devices delivering red and near-infrared light (630–850 nm) directly to the eye or periorbital area, aimed at stimulating mitochondrial energy production in retinal cells and supporting the treatment of conditions including age-related macular degeneration, dry eye, and myopia progression in children. [2]
The Scientific Evidence
The evidence for these two applications is at very different stages of development, and the consumer market has failed to communicate this distinction.
Blue-light blocking has a plausible, well-understood mechanism but mixed clinical trial results, with a 2023 Cochrane review concluding that existing evidence is inconclusive for most claimed benefits outside of a specific evening-use protocol. [3]
Photobiomodulation for the eye, by contrast, has FDA authorization for one specific indication (dry age-related macular degeneration) and accumulating clinical trial data for others, but comes with strict caveats about dosing, device quality, and the need for professional oversight. [4]
Light is not just illumination. It is the primary signal that sets the human circadian clock. The internal timing system governing sleep, hormone secretion, immune function, metabolism, and mood.
The photoreceptors responsible for this are not the rods and cones used for vision. They are a separate class of retinal ganglion cells containing the photopigment melanopsin, most sensitive to light at approximately 480 nm, squarely in the blue portion of the visible spectrum. [1]
When these cells detect blue-enriched light, they signal the suprachiasmatic nucleus (SCN), the master circadian clock in the hypothalamus, to suppress melatonin secretion and maintain wakefulness.
This is biologically appropriate during daylight hours. The problem is that modern artificial lighting, and especially smartphone and computer screens, deliver this same blue-rich signal well into the evening.
Here are two examples.
Finland's latitude creates an extreme annual light variation. In Helsinki (60°N), the sun rises and sets within roughly 6 hours in December. In Lapland (above 66°N), it does not rise at all for weeks.
The population's circadian system is chronically under-entrained during winter. People receive insufficient morning light to set the clock forward, while simultaneously being exposed to artificial blue-light-rich screens throughout the evening that suppress the melatonin onset signal further. [7]
Studies using the Finnish general population database show 21% of Finns meet criteria for seasonal affective disorder (SAD), and 70% report seasonal variation in sleep duration, mood, energy, and social activity. [6] A population-based study of rural Finnish communities found winter SAD prevalence of 9.5%, among the highest measured in any European population. [5]
The core pathophysiology of SAD involves a circadian phase delay: the biological night is shifted later than the social schedule, producing chronic misalignment. [8]
Germany faces a different but related challenge. German adults now average over 10 hours of screen time daily across all devices, with smartphone use concentrated heavily in the 2-3 hours before sleep.
This creates the biochemical equivalent of watching a sunrise before bed: a surge of blue-wavelength light that delays melatonin onset by an average of 1.1 hours when sustained for just 2 hours of evening exposure. [9]
At the population level, this means the majority of working-age Germans are sleeping later than their circadian biology dictates, accumulating chronic sleep debt, and experiencing the downstream metabolic and immune consequences.
Germany also sits between 47° and 55°N. Not as extreme as Finland but still experiencing meaningfully shortened winter photoperiods that compromise morning light entrainment for four to five months of the year.
The evening blue-light problem and the morning light insufficiency problem are additive: both delay the circadian clock in the same direction.
The photopigment melanopsin, expressed in intrinsically photosensitive retinal ganglion cells (ipRGCs), has a peak spectral sensitivity at approximately 480 nm, with the most effective range for melatonin suppression between 446 and 477 nm. [10]
These cells project via the retino-hypothalamic tract directly to the SCN, which relays the signal through a polysynaptic circuit to the pineal gland, suppressing melatonin synthesis. [11]
Critically, this non-visual photoreception pathway is distinct from pattern vision, it persists in people with severely impaired visual acuity, and it operates at light intensities far below those required for comfortable daytime vision.
A PNAS study exposing 100 participants to 6.5-hour monochromatic light exposures found that over sustained exposure, the circadian response is dominated 82–100% by melanopsin activation, with S-cone contributions dominating only the first 1.5 hours. [12]
This has a practical implication: even low-intensity blue light sustained over a long evening screen session accumulates significant melanopsin activation. The typical two-hour pre-sleep phone use is sufficient to meaningfully delay melatonin onset.
Blue-light-blocking glasses (BBGs) filter short-wavelength light before it reaches the ipRGCs, creating what researchers call "virtual darkness”: the eye perceives a lit environment for visual purposes, but the circadian system receives a significantly reduced signal. [13]
The degree of filtering varies enormously by lens type and tint. A 2025 ARVO study evaluated 26 commercially available products using the melanopic daylight factor (mDFD) metric, a standardised measure of circadian light suppression. [14]
The results were stark: clear and near-clear lenses marketed as 'blue blockers’, including numerous popular brands, produced no meaningful reduction in melanopic input.
Only lenses with a dark amber or orange tint (mDFD ≥ 1.0) provide sufficient filtering to justify the blue-blocking label. The study found mDFD values between 1.0 and 2.0 to represent the best balance between circadian protection and preserved vision under typical lighting conditions. [14]
This is where the story becomes more complicated. The mechanism is sound. But the evidence for it from interventional trials is inconsistent,
That the inconsistency is largely a product of using underpowered studies, poorly specified products, and failing to control for timing of use.
A 2023 Cochrane systematic review, widely considered the highest standard of evidence synthesis, examined 17 randomized controlled trials of blue-light-filtering lenses.
Its conclusion was unambiguous: blue-light filtering spectacle lenses probably make no significant difference to eye strain associated with computer use, and evidence for sleep improvement is inconclusive. [3] The review found no evidence that these lenses protect against retinal damage.
Interestingly, the reviewers noted that most included products were clear or near-clear lenses: precisely the category the ARVO mDFD study subsequently confirmed to be non-functional as circadian filters.
This finding should not be misread as "blue-light glasses don't work." It should be read as "most blue-light glasses sold to consumers don't filter enough light to produce a measurable effect, and the trials tested the wrong products."
The reviewer itself acknowledged that certainty was limited by evidence quality and short follow-up periods.
Studies using dark amber or orange lenses, those meeting the expected functional filtering threshold, tell a more positive story.
A systematic review of 29 experimental publications on evening BBG use found substantial evidence for reduced sleep onset latency in patients with sleep disorders, jet lag, and shift work schedules. [15]
Three of six RCTs in a separate meta-analysis found significant improvements in sleep quality scores with properly filtering lenses.
The other three found no significant difference, with variation attributed to differences in study populations and protocols. [16]
A 2025 meta-analysis of actigraphy-based RCTs (the most objective sleep measurement method) found non-significant reductions in sleep onset latency of approximately 4.86 minutes with BBGs. A modest effect that falls short of significance given the small sample sizes (n=49 across 3 trials). [17] The authors explicitly called for larger, better-powered trials with standardised amber lens protocols before firm conclusions can be drawn.
There is also preliminary evidence that amber BBGs may reduce symptoms in bipolar disorder, a condition characterised by circadian dysregulation, by mimicking the effect of dark therapy. [15] Important for shift workers and frequent travellers managing jet lag, the mechanistic case is particularly strong since these individuals face acute, predictable circadian disruption that evening light management can partially mitigate.
One critically undervalued finding from the research literature: wearing blue-light-blocking glasses during the daytime is actively counterproductive.
Blue light during daylight hours is beneficial, it promotes alertness, supports cognitive function, regulates mood, and provides the morning light cue that phase-advances the circadian clock. [18]
Filtering this out during waking hours creates the conditions associated with SAD: insufficient entraining light signal, delayed circadian phase, morning grogginess, and low daytime energy.
For Finnish and Northern European users who already face critically low winter daylight levels, wearing amber BBGs outside or during daytime hours is not a minor mistake. It compounds the exact problem they are trying to solve. The evidence is clear that BBGs should be used only in the 2–3 hours before sleep, exclusively for evening screen use. [18]
The commercial blue-light-glasses market is largely unregulated, and the gap between marketed claims and measurable filtering performance is substantial. The ARVO mDFD study is particularly useful here as it provides the first standardised comparison of 26 named products.
The practical implication: consumers who buy popular clear-lens 'blue blockers' from fashion eyewear brands are, in the words of the ARVO researchers, using products that "do not deserve to be in the same category" as functional amber-tinted glasses.
Consumers are often paying for a wellness aesthetic with no mechanism for the claimed effect. Because the cost difference between non-functional clear lenses and properly specified dark amber lenses is often negligible.
The information gap is the real problem.
Photobiomodulation (PBM) is a categorically different intervention from blue-light blocking. Rather than filtering unwanted light out, it delivers specific beneficial wavelengths, typically 630–670 nm (visible red) and 810–850 nm (near-infrared), directly to retinal and periorbital tissue.
The mechanism operates at the cellular level, not the circadian level.
The primary target of red and near-infrared light in biological tissue is cytochrome c oxidase (CcO), the terminal enzyme in the mitochondrial electron transport chain, responsible for generating ATP (cellular energy). [19]
In the resting or damaged state, CcO activity is suppressed by nitric oxide binding. Red and NIR light at specific wavelengths photodissociate this nitric oxide, restoring CcO activity, increasing ATP production, reducing oxidative stress, and triggering downstream anti-inflammatory and neuroprotective signalling cascades. [20]
The retina is an especially relevant target for two reasons. First, it has one of the highest metabolic rates of any tissue in the body, photoreceptors and retinal pigment epithelium (RPE) cells consume ATP at extraordinary rates to maintain ion gradients and continuously regenerate visual pigments.
Second, the retina has a direct optical path from external light sources, it does not need to be accessed surgically or transcutaneously. Light enters the eye and reaches the retina directly, making PBM delivery here far more accessible than in any other organ. [21]
The strongest clinical evidence for ocular PBM comes from AMD research. The LIGHTSITE trials, a series of clinical studies using multiwavelength PBM (590, 660, and 850 nm) in patients with dry AMD: demonstrated improvements in visual acuity, reductions in drusen volume (the waste deposits characteristic of AMD), and slowed progression toward geographic atrophy. [22]
On the basis of this evidence, the FDA authorized the Valeda Light Delivery System, the first therapeutic option for dry AMD, making this the only ocular PBM indication currently with regulatory clearance. [23]
The authorization covers early-to-intermediate dry AMD only; it is not cleared for wet AMD and is not available as a home device — it must be administered in a clinical setting.
Perhaps the most active area of PBM research is childhood myopia, which is projected to affect 50% of the global population by 2050.
Multiple randomised controlled trials, primarily conducted in China, have found that repeated low-level red-light therapy (RLRL) at 650 nm, administered for two 3-minute sessions daily, significantly slows axial eye elongation (the primary driver of myopia progression) compared to standard spectacle correction. [24]
A 2025 meta-analysis of seven RCTs involving 691 paediatric participants found RLRL to be competitive with or superior to orthokeratology lenses and low-dose atropine, currently the gold-standard treatments, for axial length control. [25] Safety data from trials including children showed no cases of permanent vision loss, with only transient afterimages resolving within six minutes. [26]
Virtually all trial data comes from Chinese populations, where myopia prevalence and progression rates are substantially higher than in European populations.
Generalization to Western children should be done with abundance of caution. Additionally, studies suggest a rebound effect if therapy is stopped abruptly, meaning this is a maintenance intervention rather than a cure.
A 2021 clinical trial found that 660 nm LED therapy applied periocularly over four weeks significantly improved dry eye symptoms, tear production, and ocular surface health markers compared to placebo, without serious adverse effects. [27]
The proposed mechanism involves improved meibomian gland function, the oil-secreting glands at the eyelid margin that are primarily responsible for preventing tear evaporation. This represents a practical application with documented benefit in a very common condition.
A University College London study by Glen Jeffery's group found that just three minutes of 670 nm red light exposure in the morning improved colour contrast sensitivity and rod function for up to a week in adults over 40, suggesting that periodic retinal PBM exposure may support baseline retinal function as mitochondria age. [28]
The mechanism proposed: ageing retinal mitochondria consume the proton gradient needed for ATP synthesis less efficiently, and red light at 670 nm temporarily reverses this decline by restoring CcO activity.
This is one of the most intriguing findings in the field, applicable to any adult over 40 with no diagnosed eye condition, but currently supported by a small number of studies and requiring replication.
The enthusiasm in consumer markets has outpaced the evidence considerably. Several claims attached to consumer 'red light glasses' lack meaningful scientific support:
The broader issue with consumer PBM devices is dosing control. Unlike pharmaceutical interventions, light therapy can be harmful at excessive doses, a phenomenon called biphasic dose response or hormesis.
Too little light produces no effect; the therapeutic window produces benefit; too much produces cellular damage.
Consumer devices with unverified output, applied without professional guidance, may fall anywhere on this curve. For retinal tissue, which is among the most photosensitive in the body, this is not a trivial concern. [29]
Light management interventions: whether blue-light blocking; morning light therapy; or PBM, operate through mechanisms that are measurable.
For users who want objective evidence of whether their approach is working, the following biomarkers are relevant. All are testable through platforms like Aniva Health:
Blue-Light-Blocking Glasses
Red Light / PBM Devices — Buying Criteria
The distinction between blue-light-blocking glasses and photobiomodulation devices is not semantic. In effect, it is the difference between an intervention designed to protect a signal (melatonin onset) and one designed to generate energy in cells (mitochondrial ATP). Both have legitimate scientific foundations, though the evidence is mixed.
Furthermore, both are surrounded by a consumer market that overstates what they can do, undersells the conditions under which they work, and frequently sells non-functional versions of both.
A straightforward but somewhat simplistic priority ranking is this:
For general preventive use, the morning three-minute red-light protocol from the UCL work is low-risk and biologically plausible, but should be understood as exploratory rather than established standard of care.
As with all health interventions, the most valuable step before purchasing any device is understanding your own baseline. Measuring relevant biomarkers, sleep quality, cortisol rhythm, vitamin D, inflammatory markers, through a platform like Aniva Health allows you to know whether an intervention is producing measurable change rather than relying on subjective impression in a category where placebo effects are powerful and marketing is loud.
Medical Disclaimer
This article is for informational purposes only and does not constitute medical advice. All references to clinical studies are cited throughout. If you have a diagnosed eye condition, sleep disorder, or are considering any light-based therapy, consult a qualified healthcare professional before proceeding.
All references are peer-reviewed publications, systematic reviews, or regulatory sources.
[1] Wahl S, et al. (2019). The inner clock — blue light sets the human rhythm. Journal of Biophotonics, 12(12). doi:10.1002/jbio.201900102
[2] Valter K, et al. (2024). Photobiomodulation use in ophthalmology — an overview of translational research from bench to bedside. Frontiers in Ophthalmology, 4:1388602. doi:10.3389/fopht.2024.1388602
[3] Singh S, Downie LE, et al. (2023). Blue-light filtering spectacle lenses for visual performance, sleep, and macular health in adults. Cochrane Database of Systematic Reviews. PMID:37593770
[4] All About Vision / BrightFocus Foundation (2025). What to Know About Light Therapy for Dry Macular Degeneration. brightfocus.org
[5] Partonen T, Lönnqvist J. (1998). Seasonal affective disorder among rural Finns and Lapps. PubMed PMID:10082184
[6] Grimaldi-Toriz S, et al. (2016). Seasonal affective disorders associated with common chronic diseases in Finland. Journal of Affective Disorders. FINNRISK 2012 dataset, n=4,689. doi:10.1016/j.jad.2016.05.049
[7] Jääskeläinen T, et al. (2013). Finnish Institute for Health and Welfare: Vitamin D status in the Finnish population. Suomen Lääkärilehti 42/2013.
[8] Lam RW, Levitt AJ. (2007). Seasonal Affective Disorder: An Overview and Update. Annals of Clinical Psychiatry. PMC3004726.
[9] Alam M, Abbas K, et al. (2024). Impacts of blue light exposure from electronic devices on circadian rhythm and sleep disruption in adolescent and young adult students. Chronobiology in Medicine, 6:10–14.
[10] Wahl S, et al. (2019). ibid. Melatonin suppression peak sensitivity at 446–477 nm.
[11] Lockley SW, Brainard GC, Czeisler CA. (2003). High sensitivity of the human circadian melatonin rhythm to resetting by short wavelength light. J Clin Endocrinol Metab, 88:4502–5.
[12] St. Hilaire MA, et al. (2022). The spectral sensitivity of human circadian phase resetting and melatonin suppression to light changes dynamically with light duration. PNAS. doi:10.1073/pnas.2205301119
[13] Janku K, et al. (2021). Evening wear of blue-blocking glasses for sleep and mood disorders: a systematic review. PubMed PMID:34030534
[14] Santhi N, et al. (2025). Optimizing the Potential Utility of Blue-Blocking Glasses for Sleep and Circadian Health. TVST/ARVO Journals; PMC12315928.
[15] Esaki Y, et al. (2021). Evening wear of blue-blocking glasses for sleep and mood disorders: a systematic review. Sleep Medicine Reviews. PMID:34030534
[16] Downie LE, et al. (2023). Cochrane Review: Blue-light filtering spectacle lenses. ibid.
[17] Frontiers in Neurology (2025). Efficacy of blue-light blocking glasses on actigraphic sleep outcomes: a systematic review and meta-analysis. doi:10.3389/fneur.2025.1699303
[18] Blue-light-blocking lenses in eyeglasses: A question of timing (2022). PMC8897255. Expert commentary on daytime versus evening use implications.
[19] Hamblin MR. (2016). Photobiomodulation in ocular therapy — current status. PMC7738953.
[20] Tedford CE, et al. (2024). Photobiomodulation use in ophthalmology. Frontiers in Ophthalmology. doi:10.3389/fopht.2024.1388602
[21] Barathikannan K, et al. (2025). Photobiomodulation in ocular therapy: current status and future perspectives. PMC11754031.
[22] Merry GF, et al. (2024). LIGHTSITE III Trial: multiwavelength PBM improved visual acuity and reduced drusen volume in dry AMD. Retina. PMID:37972955
[23] FDA authorization: Valeda Light Delivery System for early-to-intermediate dry age-related macular degeneration. LumiThera Inc. 2023–2024.
[24] Jiang Y, et al. (2022). Effect of Repeated Low-Level Red-Light Therapy for Myopia Control in Children: A Multicenter Randomized Controlled Trial. PMID:34863776
[25] Scientific Reports (2025). Repeated low-level red-light therapy vs. conventional treatments for myopia control: systematic review and meta-analysis. doi:10.1038/s41598-025-16868-8
[26] Zhu M, et al. (2024). Safety of repeated low-level red-light therapy in children with myopia. Translational Vision Science & Technology.
[27] Solomos A, et al. (2021). 660 nm photobiomodulation for dry eye disease. Clinical Ophthalmology. PMID:34198493
[28] Shinhmar H, et al. (2021). Three minutes of 670 nm red light exposure improves colour contrast sensitivity in adults over 40. J Gerontol A Biol Sci Med Sci. PMID:34819619
[29] Hamblin MR. (2017). Mechanisms and mitochondrial redox signaling in photobiomodulation. Photochemistry and Photobiology.
second, use properly specified amber-lens glasses (not clear 'blue-light glasses') in the two to three hours before sleep during screen use. The mechanism is sound and the cost is minimal;
third, consider PBM only for specific indications (AMD, myopia control, dry eye) under professional guidance with clinical-grade equipment.
For general preventive use, the morning three-minute red-light protocol from the UCL work is low-risk and biologically plausible, but should be understood as exploratory rather than established standard of care.
As with all health interventions, the most valuable step before purchasing any device is understanding your own baseline. Measuring relevant biomarkers, sleep quality, cortisol rhythm, vitamin D, inflammatory markers, through a platform like Aniva Health allows you to know whether an intervention is producing measurable change rather than relying on subjective impression in a category where placebo effects are powerful and marketing is loud.
All references are peer-reviewed publications, systematic reviews, or regulatory sources.
[1] Wahl S, et al. (2019). The inner clock — blue light sets the human rhythm. Journal of Biophotonics, 12(12). doi:10.1002/jbio.201900102
[2] Valter K, et al. (2024). Photobiomodulation use in ophthalmology — an overview of translational research from bench to bedside. Frontiers in Ophthalmology, 4:1388602. doi:10.3389/fopht.2024.1388602
[3] Singh S, Downie LE, et al. (2023). Blue-light filtering spectacle lenses for visual performance, sleep, and macular health in adults. Cochrane Database of Systematic Reviews. PMID:37593770
[4] All About Vision / BrightFocus Foundation (2025). What to Know About Light Therapy for Dry Macular Degeneration. brightfocus.org
[5] Partonen T, Lönnqvist J. (1998). Seasonal affective disorder among rural Finns and Lapps. PubMed PMID:10082184
[6] Grimaldi-Toriz S, et al. (2016). Seasonal affective disorders associated with common chronic diseases in Finland. Journal of Affective Disorders. FINNRISK 2012 dataset, n=4,689. doi:10.1016/j.jad.2016.05.049
[7] Jääskeläinen T, et al. (2013). Finnish Institute for Health and Welfare: Vitamin D status in the Finnish population. Suomen Lääkärilehti 42/2013.
[8] Lam RW, Levitt AJ. (2007). Seasonal Affective Disorder: An Overview and Update. Annals of Clinical Psychiatry. PMC3004726.
[9] Alam M, Abbas K, et al. (2024). Impacts of blue light exposure from electronic devices on circadian rhythm and sleep disruption in adolescent and young adult students. Chronobiology in Medicine, 6:10–14.
[10] Wahl S, et al. (2019). ibid. Melatonin suppression peak sensitivity at 446–477 nm.
[11] Lockley SW, Brainard GC, Czeisler CA. (2003). High sensitivity of the human circadian melatonin rhythm to resetting by short wavelength light. J Clin Endocrinol Metab, 88:4502–5.
[12] St. Hilaire MA, et al. (2022). The spectral sensitivity of human circadian phase resetting and melatonin suppression to light changes dynamically with light duration. PNAS. doi:10.1073/pnas.2205301119
[13] Janku K, et al. (2021). Evening wear of blue-blocking glasses for sleep and mood disorders: a systematic review. PubMed PMID:34030534
[14] Santhi N, et al. (2025). Optimizing the Potential Utility of Blue-Blocking Glasses for Sleep and Circadian Health. TVST/ARVO Journals; PMC12315928.
[15] Esaki Y, et al. (2021). Evening wear of blue-blocking glasses for sleep and mood disorders: a systematic review. Sleep Medicine Reviews. PMID:34030534
[16] Downie LE, et al. (2023). Cochrane Review: Blue-light filtering spectacle lenses. ibid.
[17] Frontiers in Neurology (2025). Efficacy of blue-light blocking glasses on actigraphic sleep outcomes: a systematic review and meta-analysis. doi:10.3389/fneur.2025.1699303
[18] Blue-light-blocking lenses in eyeglasses: A question of timing (2022). PMC8897255. Expert commentary on daytime versus evening use implications.
[19] Hamblin MR. (2016). Photobiomodulation in ocular therapy — current status. PMC7738953.
[20] Tedford CE, et al. (2024). Photobiomodulation use in ophthalmology. Frontiers in Ophthalmology. doi:10.3389/fopht.2024.1388602
[21] Barathikannan K, et al. (2025). Photobiomodulation in ocular therapy: current status and future perspectives. PMC11754031.
[22] Merry GF, et al. (2024). LIGHTSITE III Trial: multiwavelength PBM improved visual acuity and reduced drusen volume in dry AMD. Retina. PMID:37972955
[23] FDA authorization: Valeda Light Delivery System for early-to-intermediate dry age-related macular degeneration. LumiThera Inc. 2023–2024.
[24] Jiang Y, et al. (2022). Effect of Repeated Low-Level Red-Light Therapy for Myopia Control in Children: A Multicenter Randomized Controlled Trial. PMID:34863776
[25] Scientific Reports (2025). Repeated low-level red-light therapy vs. conventional treatments for myopia control: systematic review and meta-analysis. doi:10.1038/s41598-025-16868-8
[26] Zhu M, et al. (2024). Safety of repeated low-level red-light therapy in children with myopia. Translational Vision Science & Technology.
[27] Solomos A, et al. (2021). 660 nm photobiomodulation for dry eye disease. Clinical Ophthalmology. PMID:34198493
[28] Shinhmar H, et al. (2021). Three minutes of 670 nm red light exposure improves colour contrast sensitivity in adults over 40. J Gerontol A Biol Sci Med Sci. PMID:34819619
[29] Hamblin MR. (2017). Mechanisms and mitochondrial redox signaling in photobiomodulation. Photochemistry and Photobiology.
