What is Digital Eyestrain?
Dr Rebecca Nowaczek
It is well known that prolonged use of digital screens can cause vision and eye comfort issues. This is known as Digital Eyestrain or Computer Vision Syndrome. There can be many factors at play, but we know that simply an increased amount of time spent on screens relates to increased symptoms. Those who spend more than 2 continuous hours on a screen everyday are most at risk of developing symptoms. Symptoms may include eyestrain (aching/soreness), headaches, blurred vision, trouble keeping or changing focus, dry eyes (burning, stinging, itching, soreness, weeping, redness), neck and shoulder pain, and muscle spasms.
So, what is a simple solution? Is it decreasing our total time on screens and taking regular breaks throughout the day? This would be a big help, as in most cases the visual symptoms that people with digital eyestrain experience are reversible with decreased screen time. However, depending on the amount of strain the individual has experienced some symptoms can persist and require ongoing management. Unfortunately, decreased screen use is not an option for many individuals. Workplaces and educational settings are heavily screen-based these days and when we finally get a break from those tasks, many turn to screens for leisure as well.
Looking at screens is an incredibly demanding task for our eyes. We are unlikely to change our lifestyles significantly anytime soon, but what we can do is better prepare ourselves for these tasks. To help prevent or reduce the symptoms of Digital Eyestrain we need to follow this equation:
VISUAL ABILITIES OF THE INDIVIDUAL > VISUAL DEMANDS OF THE TASK = COMFORT
When our visual abilities cannot keep up with the demand of our daily tasks, we start to run into trouble.
How do we minimize the impact of screens on our eyes?
1. Make sure your vision is properly corrected – viewing a digital screen is hard work for our eyes. If your vision is not properly corrected in your glasses or contact lenses, updating these can help to minimize symptoms. We will take into consideration the distance to your screen, the size of print, the contrast and the glare on the screen when prescribing screen-specific glasses to help minimize the demand on your eyes. Bringing in the specific measurements of your desk environment can be helpful in determining the best glasses for you.
2. Make sure your glasses are properly adjusted/fitted for your tasks – viewing distances and angles are often quite different for our screen-based work than our other daily tasks. If your glasses are not positioned properly (this is especially true for multifocal wearers) you may find yourself holding your head, neck and eyes in unnatural positions which will exacerbate Digital Eyestrain.
3. Make sure your desk area is setup ergonomically – If your computer screen, desk, or chair are not setup ergonomically you could be putting extra strain on your body and eyes. To comfortably view a computer screen, we should be looking slightly downward to allow for the natural convergence (inward movement) of our eyes and to minimize exposure of the front surface of our eyes. When we look slightly down our upper eyelids cover more of our eyes and help prevent unnecessary dryness. Your leg and arm bends should be close to 90 degrees and while sitting up nice and straight (no bending forward or hunching your back) your line of sight should be just over the top of your computer screen. We can advise you further in clinic on the best desk setup and lens design for your needs.
4. Dim your screen backlight – find the balance of brightness for your screen that allows you to see comfortably without causing unnecessary glare. You can often dim the backlight considerably without impacting your ability to work.
5. Regular blinking and breaks – We blink considerably less frequently when working on a visually demanding task, and while your employer will thank you for your focus and dedication, your eyes won’t! Taking regular breaks and nice full blinks goes a long way to reducing eyestrain and dryness. Try to follow the 20/20/20 rule – Every 20 minutes, take a break for 20 seconds (have lots of big blinks) and look 20 metres away (or as far as you can out the window or down a hall). This helps to relax your near focussing eye muscles and rehydrate the surface of your eyes. A simple technique that really works!
6. Avoid glare/wind - Also be aware to avoid light sources reflecting directly off your screen and avoid positioning yourself directly under a vent or air-conditioner – these will exacerbate symptoms as well.
Implementing as many of these changes as possible will give you the best chance of overcoming the demands of screens and maintaining your comfort in and out of the workplace.
What about filtering blue light?
You may have heard about the recent popularity of blue light filters to reduce or prevent digital eyestrain. So, what is this all about? Blue light filters are an additional coating on a lens which can prevent excess blue light from entering our eyes. These filters can now be added to any prescription or non-prescription glasses and are also available in intraocular lens implants (those used in cataract surgery) as well as some contact lenses.
Blue light is short wavelength light that is emitted more heavily from modern lighting and screens. We know that natural blue light is helpful during daylight hours because it can boost attention, reaction times, and mood. In the evening, however, this can cause problems. Too much blue light after sundown can interfere with our circadian rhythm (natural sleep cycle). Harvard researchers performed a study looking at the effects of 6.5 hours of exposure to blue light vs green light of the same brightness. They found the blue light suppressed melatonin (a sleep hormone) for twice as long. There have been many recent studies into the true impact of blue light on our sleep and our eye health and the jury is still out as to how significant this may be. Simply put, the best option is to avoid screen use altogether within 2-3 hours of going to sleep if you are concerned about blue light and sleep disruption. If you are an individual working night shifts on a computer or are using electronic devices at night at home, then there is an argument that a blue light filter may be beneficial for you to wear for these tasks. There are blue light apps available that can reduce the emittance directly from the device as well.
Sleep is a vital part of our health and well-being and lack of good quality sleep can have major long-term health implications. So, whether you pack the devices away or choose a filter to decrease blue light exposure in the evenings, helping yourself achieve a good sleep is great step towards staying healthy, rested, and recharged. This will give you and your eyes the best start to tackle a day in our digital world.