Visible blue light
Our position on the clinical evidence and advice relating to visible blue light
While there is evidence to suggest that digital devices can increase eye-strain for those that use them for extended periods of time and can impact on sleep patterns, there is currently no evidence to suggest that visible blue light has any effect on the development of eye conditions such as age-related macular degeneration (AMD) or glaucoma.
Coatings that filter visible blue light may improve visual comfort for some patients, or help mitigate the impact of visible blue light on sleep, but current evidence does not support making claims that they prevent eye disease. The AOP does not support any new procedures or products for which there is either contrary evidence or no supporting evidence. It should also be noted that visible blue light filter coatings typically only block around 20% of visible blue light.
This position statement reviews the evidence for the use of coatings to filter visible blue light. It also provides advice related to patient concerns about screen use and visible blue light.
What the evidence tells us
There is no peer-reviewed evidence that visible blue light is connected with eye disease. A 2016 paper reviewing the evidence concluded that short- and medium-term exposure to low-levels of visible blue light had no impact on eye health, found no evidence of damage from longer-term exposure and suggested further research.1
A 2017 systematic review concluded that there was “a lack of high quality evidence to support using BB [Blue Blocking] spectacle lenses for the general population to improve visual performance or sleep quality, alleviate eye fatigue or conserve macular health”.2
In its 2015 ruling on claims about coatings to filter visible blue light, the Advertising Standards Authority (ASA) concluded that the evidence could not substantiate the claims made for visible blue light, saying: “only full trials conducted on humans were sufficient, potentially, to support the claims. We assessed the relevant study submitted by Boots and noted that although it included a large number of participants who were followed up over several years, it was one single epidemiological study which only suggested that sunlight and not blue-violet light in particular, might be a risk factor for the early onset of age-related macular degeneration (AMD).”3
A study examined the effect of intraocular lens (IOLs) to filter visible blue light, and found no clinical evidence for the efficacy of visible blue light-filtering IOLs.4 This view is backed up by another study reporting that the evidence informing surgeon selection of IOLs is deficient.5
However, none of these studies look at the long-term effect of visible blue light exposure and eye disease.
There have been studies of the effects of visible blue light irradiation on the retinas of rats6 and rhesus monkeys.7 The length and intensity of exposure to visible blue light in these studies far exceeded that of natural daylight or screen use. Therefore, no conclusion can be drawn as to the likely effect on humans of normal exposure to visible blue light. Due to obvious ethical issues, no studies have been carried out on humans.
From reviewing available evidence, the AOP concludes that there is insufficient evidence to support the contention that visible blue light exposure from digital devices leads to ocular pathology and damage to eye health.
Screen use and sleep patterns
There is some evidence that use of digital devices which emit visible blue light in the evening, may affect the circadian cycle, and lead to delayed sleep.8 This may be because visible blue light is linked to suppression of the hormone melatonin which makes us feel sleepy. It has been suggested that digital devices should vary the light spectrum wavelengths they emit across the day to fit our sleep patterns. There are a range of other factors also linked to disrupted sleep patterns.
Excessive time spent in using near vision, for example reading, is sometimes associated with eye-strain and headaches.
AOP advice to members
Patients often express concerns about screen use to optometrists, as revealed by the following results from our 2017 Voice of Optometry survey carried out with 1131 UK optometrists:
- More than nine in 10 UK optometrists had seen patients in the past month who reported problems as a result of screen use, such as dry eyes, headaches or eye strain
- Almost as many had seen patients who were worried that screen use was detrimental to their, or their children’s, eye health
We believe that more needs to be done to educate the public about screen use. Useful advice could include:
- There is no evidence that visible blue light causes eye disease in humans
- Using screens close to bedtime may contribute to poorer sleep, which can make a person less effective during the day
- Turning off any digital devices up to an hour before sleeping can help aid sleep
- Using night settings, if your device has them, can aid sleep by decreasing the amount of visible blue light emitted by the screen during night time hours
- To avoid eye strain people should adhere to the 20/20/20 rule, every 20 minutes, look away from your screen at something at least 20 feet away for 20 seconds
- Have a sight test every two years, or more often if your optometrist recommends it
- Tosini G, Ferguson I, Tsubota K (2016) Effects of blue light on the circadian system and eye physiology. Molecular vision and genetics in vision research, 22(61)
- Lawrenson JG, Hull CC & Downie LE (2017) 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 PhysiologicalOptics ; 37: 644–654. https://doi.org/10.1111/opo.12406
- Advertising Standard Authority (2015) ASA Ruling on Boots Professional Services Ltd t/a Boots Opticians Ltd published online 28 October 2015
- Lavric A, Pompe MT (2014) Do blue-light filtering intraocular lenses affect visual function? Optometry and Vision Science, 91(11), 1348-54
- Li X, Kelly D, Nolan J M, Dennison JL, Beatty S (2016) The evidence informing the surgeon’s selection of intraocular lens on the basis of light transmittance properties. Eye, published online 9 December 2016
- Seko Y, Pang J, Tokoro T, Ichinose S, Mochizuki M (2001) Blue light-induced apoptosis in cultured retinal pigment epithelium cells of the rat. Graefe's archive for clinical and experimental ophthalmology
- Ham WT, Ruffolo JJ, Mueller HA & Guerry D (1980) The nature of retinal radiation damage: dependence on wavelength, power level and exposure time. Vision Research, 20(12)
- Cajochen C, et al. (2011) Evening exposure to a light-emitting diodes (LED)-backlit computer screen affects circadian physiology and cognitive performance. Journal of Applied Physiology, 110(5), 1432-1438
Read the rest of the AOP position statements.