Digital eye strain or computer vision syndrome is characterized by visual disturbance and/or ocular or non-ocular discomfort associated with viewing digital display units. The term ‘computer vision syndrome’ has been used for nearly 30 years in medical literature but with the widespread popularity of other digital devices such as laptops, smartphones and tablets, ‘digital eye strain’ now seems more comprehensive and appropriate.

Symptoms of Digital Eye Strain 

Digital eye strain may present as a single ‘obvious’ symptom or a vague collection of symptoms that individuals often describe as ‘tired’ or ‘heavy’-feeling eyes. Common symptoms include:
•     dryness
•     sore eyes
•     burning or stinging eyes
•     blurred vision
•     watery eyes
•     headache
•     light-sensitivity
•     poor concentration
•     neck, shoulder and/or back pain

Causes of Digital Eye Strain

Blinking Frequency – Blinking helps keep the front surface of the eye healthy, as most blinks initiate the cycle of tear secretion, distribution, evaporation and drainage. As we stare at our digital devices, we only blink 5-7 times per minute, a 55-66% reduction compared to the average 15 times per minute under relaxed conditions!1 Many researchers believe that decreased blink rate is the primary cause of dryness among visual display unit users.2,3 Inadequate blinking not only only fails to lubricate the ocular surface, causing symptoms of dryness, it may also cause blurred vision.

Dry Eye – Dryness is commonly experienced by individuals with otherwise healthy eyes who are avid device users. As discussed above, changes in blink characteristics likely play a large role. There are other environmental and individual factors that can exacerbate dryness when using devices. Office environments often feature low humidity, ventilation fans, air conditioning and airborne dust/toner particles, which may contribute to dry eye. Digital device users who wear contact lenses are at an increased risk of digital eye strain because contact lenses interrupt with normal tear physiology, contributing to symptoms of dryness.4

Glare – Commonly experienced by computer users, glare can reduce reading speed5 and contribute to digital eye strain. The visual display unit unit is often the source of glare, but it can also come from the environment, such as improper desk lighting.

Refractive Error – Uncorrected, or an incorrect prescription for, myopia, hyperopia, astigmatism or presbyopia can make computer work less clear and comfortable. Depending on your condition, your eyes could be exerting extra focusing effort or be forced to work harder to maintain a clear image when viewing the computer screen.

Ergonomic Factors – We face a bit of ‘chicken or egg’ dilemma when discussing ergonomics in the context of digital eye strain. On one hand, an unfavourable ergonomic setup can contribute to visual symptoms. For example, if one’s computer monitor is positioned too close to their eyes and directly under a source of glare (e.g. fluorescent light), it is likely to cause their eyes to feel tired and sensitive to the light after a short period of viewing the screen.

On the other hand, non-ocular symptoms such as neck, back and shoulder pain are generally considered part of the syndrome of digital eye strain. When individuals are experiencing ocular symptoms such as blur while viewing their monitor, their posture is likely to change. They may lean toward their screen and/or slouch in their chair, putting a strain on the neck and back.

Blue Light – Whether using a computer, phone, TV or tablet, these digital sources emit blue light, the part of the visible spectrum with the shortest wavelength and highest energy. Many researchers and clinicians speculate that blue wavelength light emitted from devices contributes to digital eye strain. Blue wavelengths are scattered more than others within the eye. This may create a “visual noise“ that reduces contrast and increases the effort required to maintain visual focus. Evidence to support this association is lacking and there is little research to support the use of blue-blocking filters as a clinical treatment for digital eye strain.6 Randomized clinical trials are needed to provide high quality evidence.

Tips To Reduce Digital Eye Strain

Position your screen about an arm’s length from your eyes and 20 degrees below eye level. When sitting up straight, you should just be able to see over the monitor.

Minimize glare on screens by using dimmer switches on lights and anti-glare screen covers. Consider positioning your computer screen so that it sits perpendicular to windows and other bright light sources. If you are having trouble locating the source of the glare, turn off the monitor and tilt/swivel your dark screen until the reflection disappears.

Keep your screen free of fingerprints and dust, as both can reduce visual clarity and contribute to glare. Try a clean, dry microfibre cloth first. If that doesn’t do the trick, try adding a small amount of distilled water or fluid specifically designed for cleaning monitors; never spray anything directly only your screen.

Use the “20-20-20 rule”. Take a 20 second break every 20 minutes and focus your eyes on something at least 20 feet away (the water cooler, possibly?). This will give your eyes a much-needed break and help to reduce some of the symptoms mentioned earlier.

Remember to blink! Relieve discomfort from dry eyes by using artificial tears and remembering to blink. Consult your optometrist to determine which eye drops are best to relieve your dry eyes or if there are other strategies that you can employ.

Ask your optometrist about blue light-blocking coating for the lenses in your glasses.  Blue light emitted from screens is scattered more within the eye, reducing contrast and potentially contributing to eyestrain.