Facts, Fiction and some friendly tips

There’s loads of talk about “blocking lenses” to help prevent eye damage from the blue light that comes from computer, tablet and phone screens. And lots of it’s pretty contradictory.

Your Dresden Freunde love a good bit of myth-busting! So here we’re going to delve into the misconceptions about blue light, look at the known facts and how they apply to you, your kids and your work, and suggest ways to minimise harm to your eyes.

First, what you really want to know – do you need blue light blockers or not? Well based on the evidence, we at Dresden don’t believe blue light is, in itself, damaging to your eyes (though it can definitely interfere with sleep by disrupting your circadian rhythms). It’s the amount of time we spend looking at screens – and how we do it – that’s the real problem, causing digital eye strain.

UV light and blue light – they’re different!

Ultraviolet radiation is invisible, so technically it’s not even light! It comes from sunshine, some lasers, and things like welding and tanning devices. There are different classes of UV radiation (you’ve probably heard of UVA and UVB), and some parts of the eye are better at blocking UV than others, but prolonged exposure can cause serious damage to your eyes1.

You can protect against UV by wearing a hat and sunglasses, prescription glasses or even most contact lenses which have full UV protection. Dresden sunnies and prescription sunglasses are Category 3, meaning they provide the maximum (100%) possible protection against UV, whilst also being suitable for driving.

What’s more, our clear Zeiss lenses also provide great UV protection: our ‘standard’ 1.5 index lenses block out  91% of UV light and our higher index lenses, like 1.6 and 1.67, give you 100% UV protection.

Visible blue light is everywhere because it’s in sunlight, as well as digital screens (TVs, computers, laptops, smartphones and tablets), electronic devices, and fluorescent and LED lighting. But blue light is far less harmful than UV. (Phew!) In most situations, it would take months of continuous exposure to blue light to cause any damage to your eyes.

But we’re being exposed to more and more blue light, as computers and digital device displays become ingrained in everyday life. Not just at the office, but for staying connected, entertained and informed, and – for kids – learning at school.

Blue light: the good and the bad

A particular spectrum of blue light (in the turquoise range) may have some real benefits. Some studies show it does good things for your sleep patterns2, and it may help fight the “winter blues” (there are even lights designed to help based on this exact theory)3. There’s also some evidence that blue light could help reduce the development of myopia (near-sightedness)4.

But. (Always a But.) Blue light can affect melatonin levels and change your sleep patterns. That’s been well established5. And when it comes to the digital eye strain we get from being glued to our screens, poorer screen contrast due to blue light does make that strain worse.  

There have also been several studies suggesting blue light could be a risk factor for macular degeneration, but the fact is, it has way less impact than exposure to sunlight, smoking and age6. The American Academy of Ophthalmologists has even gone so far to say there is no evidence blue light causes any irreversible damage to our eyes7.

Cutting down your exposure to blue light

Rest breaks and reducing the time you spend looking at screens can obviously help, but easier said than done.

You can also easily change your screen settings – there are apps for this (of course!). F.Lux (for Windows, macOS, Linux, Android and iOS), Twilight (Android), Nightshift mode (iPhone), Nightstand mode (Apple watch) all help reduce the amount of blue light emitted.

And of course, you can get blue light blocking glasses. If you’re considering this, ask us at Dresden about our Zeiss lens Blue coating. It’s no big deal – we take the same simple, affordable approach as with all our glasses, prescription or sunnies. Non-prescription blue light blocker Dresdens are $69 and prescription ones are from $229.

A bit more about digital eye strain

Who doesn’t like some good statistics? Australians spent an average of 9.4 hours on devices every day. Office workers spending 11.4 hours on average8. Altogether, we looked at our smartphones more than 440 million times a day, with 75% of us regularly multi-tasking across multiple screens and devices at once9.

This reliance on all things digital is across all ages and all parts of society. So it’s probably not a huge surprise that two out of three adults experience digital eye strain10. You, your family and friends are likely to be among them, with symptoms like:

  • Dry, itchy, burning or red eyes
  • Blurred vision
  • Fatigue
  • Headache
  • Neck, shoulder and back pain

What can you do about digital eye strain? If you can cut down the time you spend looking at screens, it’s a great start.

If you work with computers all day11:

  • Take regular breaks using the 20-20-20 rule: every 20 minutes, look away to something at least 20 feet away, for at least 20 seconds and blink, blink and blink!
  • Think about a matte screen filter to reduce screen glare
  • Adjust your room lighting and and try increasing the contrast
  • Try to position all devices the same distance away from you so that you don’t have to constantly change focus
  • Position devices slightly below eye level as this decreases the amount the eye is open, causing less strain on the tear film which aids in minimising dry eyes
  • Have plants around the office to humidify and detoxify the air
  • Speak to your optometrist for further advice if you still have sore and dry eyes

If you wear multifocals, and find you need to lift your chin to see the screen when working on a desktop computer, think about lenses designed specially for desktop computer use.

UV protection matters more than blue light blocking

So what’s our advice? Blue light exposure can mess with your sleep, so blocking lenses can be helpful for getting enough shuteye.

But UV is your real enemy and causes proven damage. Wearing lenses with 100% UV protection (either clear or tinted) is the protection your eyes need most of all!

Ultraviolet Radiation as a Risk Factor for Cataract and Macular Degeneration Roberts, Joan E Ph.D. Eye & Contact Lens: July 2011, Volume 37, Issue 4, p246-249

Blue-enriched white light in the workplace improves self-reported alertness, performance and sleep quality, Antoine U Viola, Lynette M James, Luc JM Schlangen and Derk-Jan Dijk, Scandinavian Journal of Work, Environment & Health, Vol. 34, No. 4 (August 2008), pp. 297-306.

Philips goLITE BLU

Development of eye enlargement of domestic fowl subjected to low intensity light, P. C. Harrison, A. B. Bercovitz, G. A. Leary, International Journal of Biometeorology, December 1968, Volume 12, Issue 4, pp 351–358.

Blue-enriched white light in the workplace improves self-reported alertness, performance and sleep quality, Antoine U Viola, Lynette M James, Luc JM Schlangen and Derk-Jan Dijk, Scandinavian Journal of Work, Environment & Health, Vol. 34, No. 4 (August 2008), pp. 297-306.

Retinal sensitivity to damage from short wavelength light, William T. Ham Jr, Harold A. Mueller & David H. Sliney, Nature volume 260, pages 153–155 (11 March 1976)

American Academy of Ophthalmology

The New Daily

Reddy SC et al. Computer Vision Syndrome: a study of knowledge and practices in university students. Nepal J Ophthalmol 2013; 5(10): 161-168. (found Prevalence 89.9)

10 Ernst & Young (2016). Digital Australia. Sydney, NSW. Deloitte (2015). Mobile Consumer Survey – The Australian Cut. Sydney, NSW. Eyes Overexposed: The Digital Device Dilemma, 2016 Digital Eye Strain Report, The Vision Council, US.

11 American Academy of Ophthalmology