Macular degeneration, or age-related macular degeneration, is a condition that causes our central vision to blur, due to the deterioration of the macula — a small area in the centre of the retina (the light-sensitive part of the eye). The condition usually affects older people, making it challenging for them to drive, read, recognise faces, and do anything that requires sharp central vision.

There are several common risk factors for macular degeneration, including age, smoking, obesity, high blood pressure, and a family history of the condition. More recently, however, some research has begun to look into whether blue light, which typically comes from the sun and screens, can play a role in the condition.

Here, we’ll take a look at what the research says about the connection between macular degeneration and blue light.

What is blue light, and what are common sources of it?

Blue light is a part of the electromagnetic spectrum which consists of electromagnetic radiation from the sun, this means it can be harmful to various cells in the human body. It is also one of the only parts of the spectrum that’s visible to the human eye.

The largest source of natural blue light is sunlight (that’s what makes the sky look blue), but it’s also emitted from digital screens, such as smartphones and computers, in addition to fluorescent and LED lights, and televisions. These screens all rely on LED technology, which has individual green, red, and blue diodes to provide the full spectrum of colour to the viewer. The backlit displays of smartphones, tablets, and laptop computers produce the maximum amount of artificial blue light.3

Can blue light damage your eyes?

The reason blue light is concerning is because it has the shortest wavelength and highest energy among all the colours in the visible spectrum. Research is therefore being undertaken to determine whether blue light may be damaging to the eyes in high doses.5

One reason for believing that blue light can damage your eyes is because the cornea and lens in your eye, which are effective in blocking UV radiation from reaching the retina, cannot prevent visible blue light from passing through — and virtually all of it reaches the retina.5 This is thought to have more of an impact on children, as they have more transparent crystalline lenses and are, therefore, more sensitive to blue light compared to adults.5

It’s important to remember, however, that though there is thought to be a link, the effects of blue light on the eyes are still being investigated — and so the jury is still out.4

What is the link between blue light and macular degeneration?

Similarly to the research on blue light’s effect on general eye health, the link between blue light and macular degeneration has mixed opinions. Some studies suggest that exposure to blue light from screens can contribute to not only macular degeneration, but also cataracts and other serious eye diseases through degradation and damage of the retinal cells.6 However, there isn’t any strong enough scientific evidence to support the association between blue light exposure and macular degeneration as of yet.7

It is believed that the amount of blue light emitted by consumer electronics is small, and filters in these devices already effectively shield the user’s eyes.3 Some experts even believe that, when compared to the risks of aging, obesity, high blood pressure, and smoking, exposure to blue light is negligible in terms of risk of damage to the retina.3

How to reduce your blue light exposure?

Though the jury’s still out on whether blue light from digital devices can increase the risk of macular degeneration, experts agree that the use of these devices can disrupt the circadian rhythm (the body’s natural sleep-wake cycle) by causing stimulation.3 Doctors recommend limiting screen time, especially in the two to three hours before going to bed when blue light can have the maximum impact on the biological clock.4 People who work on computers for long periods should follow the 20-20-20 rule which means taking a break every 20 minutes to look at an object 20 feet away for 20 seconds to reduce eye strain.4

To learn more about how digital devices can affect your eye health, for example by causing eye strain and and headaches, head over to here for more information

References

1. NASA Science. (no date). Tour of the Electromagnetic Spectrum. [Online]. Available at: https://science.nasa.gov/ems/0... [Accessed 30 October 2019].
2. Live Science. (no date). What is Ultraviolet Light? [Online]. Available at: https://www.livescience.com/50... [Accessed 30 October 2019].
3. Harvard Health Publishing. (no date). Will blue light from electronic devices increase my risk of macular degeneration and blindness? [Online]. Available at: https://www.health.harvard.edu... [Accessed 30 October 2019].
4. American Academy of Ophthalmology. (no date). Should You Be Worried About Blue Light? [Online]. Available at: https://www.aao.org/eye-health... [Accessed 30 October 2019].
5. The Canadian Association of Optometrists. (no date). Blue Light – Is there risk of harm? [Online]. Available at: https://opto.ca/health-library... [Accessed 30 October 2019].
6. Nature Scientific Reports. (no date). Blue light excited retinal intercepts cellular signalling. [Online]. Available at: https://www.nature.com/article... [Accessed 30 October 2019].
7. Fletcher AE, Bentham GC, Agnew M, et al. Sunlight Exposure, Antioxidants, and Age-Related Macular Degeneration. Arch Ophthalmol. 2008;126(10):1396-1403. [Online]. Available at: https://jamanetwork.com/journa... [Accessed 30 October 2019].