This is frustrating as there is ample evidence available to show that blue light may cause damage to our eyes.
Let’s take a look at the evidence in the academic literature.
What is Blue Light?
Before we delve into the literature we should first define what blue light is. For more detailed information you can check out our earlier article “what is blue light”. Blue light is high energy visible (HEV) light that falls between 400nm and 495nm. Blue light is emitted from the sun (natural light) and from artificial sources like LEDs and Fluorescent lights. Artificial blue light is found in smart phones, house and office lights, laptops, fridges and our TVs. Artificial blue light has been linked to digital eye strain and circadian disruption.
HEV blue light between 415nm and 455nm is the most harmful and can cause irreversible retinal damage according to a study in 2014 (1) showing light-induced retinal damage and potential benefits and side effects of blue light-filtering intraocular lens.
As blue light is a short wavelength light the focus is actually not located toward the middle of the retina, rather in the front. What this means is that long exposure to blue light, like working at a computer all day, can cause visual tiredness and near-sightedness.
How does blue light impact the Cornea?
The cornea is located at the front end of the eye and is the first part of the eye that receives blue light. A study in 2015 showed that the survival rate of corneal epithelial cells after exposure to blue light actually decreased. The same study by Zheng et al, also showed an increase in reactive oxygen species (ROS) in the cells in the cornea following exposure to blue light. ROS cause cell damage so their increase in production by exposing ourselves to artificial blue light is not a good idea for eye health.
Another study in 2016 by Lee HS et al showed that the increase in ROS led to oxidative damage in the eyes. The study showed that the treatment for this oxidate stress is a dose of antioxidants. This is interesting as the most powerful antioxidant we can produce in Melatonin which is produced in the absence of blue light. It can therefore be hypothesized that the absence of blue light after sunset (ancestrally or by wearing blue light glasses) and the onset of melatonin production is nature’s antidote to the oxidative stress caused by blue light during the day.
In 2014 a study emerged that showed that the microvilli located in the cornea lose support and stability when exposed to blue light. This is what happens when we develop dry eyes when working at a computer all day. Blue light is damaging your eyes, this is very clear.
Blue light’s effects on the lens
When you google “how are cataracts formed” you would find a sea of information pointing to UV light. However, this may be misleading as there is other evidence available to suggest blue light is the cause of cataracts. Whilst we cannot ignore the evidence supporting excessive UV exposure to the formation of cataracts a study in 2003 showed that blue light may be another cause. As far back as 1980 people knew that that lens can effectively filter short wavelength blue light in order to reduce rental damage. The lens contains various enzymes and proteins that absorb blue light and prevent damage to the retina in the eye. Overtime the activation of these proteins and enzymes produce yellow pigments in the lens proteins causing the lens to darken and eventually turn yellow. In order for the lens to continue filtering blue light effectively it has to undergo a transparency in colour which leads to cataract formation.
Blue light and retinal damage in the eye
Blue light has been shown to pass through the lens and cause damage to the retina. There are many studies showing that blue light can cause retinal damage. In 2016 a study has conducted which showed blue light from LED’s causes retinal damage.
Some studies have also shown that exposure to HEV blue light can speed up macular degeneration.
The mitochondria seem to be the main focal point of oxidative stress caused by blue light. Our mitochondria are the powerhouses of our cells and drive energy production. Oxidative stress in the mitochondria could impair energy production which could lead to fatigue related diseases.
In 2017, Ishii and Rohrer released a study which showed that blue light stimulated local oxidative stress in the retina. . The study also showed that blue light may cause degradation of retinal pigments.
Blue Light and Poor Eyesight
In 2011 a survey was conducted with school children which looked into the impact on screen reading on their visual acuity. The results showed a strong correlation between screen time and the development of poor eyesight in children. Higher incidences of near-sightedness were also closely corelated with an increase in length of screen time observed.
Effects of Blue Light on Circadian Rhythm
There is unequivocal evidence that shows that blue light influences your circadian rhythms. This is especially true at night when exposure to blue light has been shown to disrupt our sleep. Blue light after sunset has been shown to damage the retina and affect sleep quality.
Sleep disorders which have been caused by exposure to excessive blue light can increase instances of digital eyestrain and dry eyes.
How to stop blue light damaging your eyes
Studies have shown that time spent outdoors can prevent the development of myopia. More time spent outside under the sun will mean we not only get good natural blue light from the sun but also healing red light and invisible infrared light. Take regular sunbreaks away from digital devices where you can.
Wearing the best computer glasses during the day will help reduce the amount of blue light damaging your eyes. A pair of blue light filtering computer glasses from BLUblox should be your go to pair of blue light glasses. Not all blue light glasses focus on damaging blue light, instead focussing on violet light where no evidence exists of this type of light causing any negative damage to the eyes.
After sunset in order to protect your eyes from circadian disruption you should wear a pair of blue light glasses that block blue light and green light between 400nm and 550nm. This will protect your eyes from blue light damage and improve your sleep. The best blue light blocking glasses are Sleep+ from BLUblox.
When Harvard Health and Forbes talk about the lack of evidence that blue light causes eye damage they clearly are not looking hard enough. There is plenty of evidence to suggest blue light causes eye damage and blue light management techniques should be adopted in order to mitigate these potential negative effects.
More information on blue light and the best blue light management products can be viewed at blublox.com
- Bi WM, Sun K. Light-induced retinal damage and potential benefits and side effects of blue light-filtering intraocular lens. Recent Advances in Ophthalmology. 2014;34(3):289–293
- Xue L, Bo YU, Hong X. The establishment of a rat model for experimental retinal photic injury and observation of pathological changes in the retina. Chinese Journal of Optometry & Ophthalmology