Dr Deborah Lee, Dr Fox Online Pharmacy, highlights the symptoms of digital eye strain and explains what can be done to treat it
Do you, like me, suffer from digital eye strain (DES) – otherwise known as computer vision syndrome? It’s very unpleasant.
Most of us spend far too much time every day using digital devices, such as smartphones, and computers. As a result, DES has become a common health problem. Estimates suggest 50% of us may be suffering from unpleasant symptoms associated with computer-induced eyestrain.
- What are the symptoms of DES?
- What can be done about it?
It’s time to read on and find out.
What is DES?
DES has been recognised as a medical condition for over 20 years. Symptoms can arise from the use of any digital device, including smartphones, iPads, and laptop and desktop computers.
A comprehensive review of DES was published in the British Journal of Ophthalmology (April 2018) and much of the information here, originates from this excellent paper.
DES can affect any one of us, in any age group. Did you know –
- By the time they are 3 years old, 68% of children regularly use a computer.
- 45% of UK adults report using a computer for 4 hours and forty-five minutes per day.
- In older age groups, internet usage has doubled in recent years. 75% of adults aged 65-74, now regularly using a computer.
- 87% of young adults aged 20-29 years, report using two digital devices simultaneously while surfing the net!
Symptoms of DES
How would you know if you are experiencing DES? Symptoms of DES include –
- Blurred or double vision
- Dry eyes, or weepy eyes
- Burning sensation
- Eyes feel sore, tired, hard to keep open
- Red eyes
- Increased sensitivity to light
- Neck and shoulder pain
Working eye muscles
Accommodation is the medical term used to describe what happens, when the eye muscles (ciliary muscles) contract, to change the shape of the lens, so you can achieve sharp, clear vision.
- For near vision, when you are looking at the screen, your eyes constantly need to accommodate. This means your eye muscles are persistently working hard, all the time you are trying to focus on the computer screen.
- When you look away from the screen, your eye muscles relax, to enable you to focus on something in the distance.
Long periods of near vision put your eye muscles under strain.
Some DES symptoms are linked to a medical condition called ‘dry eye.’ An incredible 50% of the population suffer from dry eye. Although it is most common in older people, dry eye can affect any age group.
Dry eye is important because it is a contributory factor to DES. The act of blinking spreads a film of naturally produced tears over the front of the eye, keeping the cornea moist. When you stare at a computer screen for long periods, this causes you to blink less often. As the rate of blinking slows, the cornea starts to dry out. Your eyes begin to feel irritable, gritty, and sore.
Dry eye – causes
Dry eye can be present for a variety of reasons. However, if you have dry eyes, and use a computer, this can exacerbate DES symptoms.
One 2016 meta-analysis, compared published studies on the prevalence of dry eye disease in office workers using visual display terminals. The authors included 16 studies, with a total of 11, 365 office workers. Dry eye disease was reported by 49.5%.
Dry eye can be caused by the following:
- Medication – such as antihistamines, antihypertensives, decongestants, diuretics, non-steroidal anti-inflammatory drugs (NSAIDs), steroids, and some antidepressants.
- Use of certain eye drops – such as glaucoma drops, or due to toxicity from the preservative in many proprietary eye drops.
- Skin disease which affects the eyelids – such as eczema or acne rosacea
- Meibomian gland dysfunction – Meibomian glands are found in the eye. They produce an oily substance called meibum, which stops tears from evaporating from the surface of the eye. The gland may become dysfunctional, usually associated with age, and hormonal factors.
- Eye allergies – examples of eye allergies include allergy to pollen, dust mite, mould, cigarette smoke, and perfume.
- Vitamin deficiencies – Vitamin A, Vitamin C, and zinc, are especially important for good eye health.
- Prolonged use of contact lenses – Leaving contact lenses in situ for too long can cause dry eyes.
- Chronic herpes infection in the eye – Chronic herpes infection is thought to damage the nerve supply to the lacrimal duct and reduce tear production.
- Menopause – Hormone deficiency is associated with increased risk of dry eye.
- Auto-immune conditions – In Sjogren syndrome, the body produces antibodies that destroy the lacrimal glands. Other autoimmune conditions also affect the eyes such as rheumatoid arthritis, thyroid disease, and SLE.
- Environmental factors – These can all cause eye irritation. Examples include cigarette smoke, pollution, chemical fumes, and low humidity.
DES and visual fatigue
Using a digital screen affects the normal, subconscious, workings of the eye. Without you being aware, when you stare at the computer screen, your eyes are working hard to focus and create sharp images.
- Critical flicker-fusion frequency (CFF) – The brain perceives the natural pulses of light, which pass through the eye, as a continuous light beam. The CFF is the light frequency at which this happens. The CFF tends to decline with increasing eye strain and fatigue. As CFF falls, there seems to be an increase in DES symptoms.
- Blinking and squinting – The eye relies on blinking to continuously spread tears across the cornea. Studies have shown the blink rate falls considerably with time spent in front of the computer.
One 1991 study reported a blink rate of 18.4 blinks/per minute before the study, falling to 3.6/minute, during the period of computer use. It also seems that the harder the computer task, the more concentration is required, the larger the fall in blink rate.
- Accommodation difficulties – Even people with normal vision may develop problems with accommodation during a protracted computer task.
- Pupil light reflexes – During or after a long computer task, the pupil may sometimes remain slightly constricted, perhaps due to spasm in the ciliary muscles or papillary sphincter.
The effects of blue light
Blue light is short-wave light (400-500 nm) emitted from digital screens, but also from electronic devices such as TV screens, and some LED bulbs. Eye specialists believe that most blue-light emitting devices, do not produce enough blue light to cause damage to the retina. There is also a lack of evidence that blue-light blocking devices, such as glasses or screens, have health benefits. You should never look directly at any high-intensity light source, just as you should never look at the sun.
However, exposure of the retina to blue light can disrupt the release of the sleep hormone melatonin, and cause sleep difficulties. Try to limit your use of mobile phones, computers, and TV’s, in the hour or two before bedtime.
The use of anti-blue light-emitting glasses and screens is sometimes advocated. However, there is a lack of evidence these are effective, and fines have recently been issued for inappropriate advertising of these devices.
How to reduce DES
If you think you might be suffering from DES here are some ways you can help manage the condition. There is a lot that can be done to help.
Have an eye check with an optician
- You may be entitled to a free NHS eye test. You should have your eyes tested every 2-years. See an optician without delay if you have any concerns about changes in your vision. The optician will advise about correcting any visual defect, but also tell you if you have characteristic findings of dry eye.
Treating dry eye
- Use eye drops – These are artificial tears to help keep the surface of the eye moist. Your pharmacist will advise you whether to use drops, gels, or ointments. Apply the drops as directed. You may be advised to apply a couple of drops before you start to use your digital device.
- Ensure the room where you keep your computer, well-humidified. You can do this simply by having a bowl of water standing nearby.
- Fans and air conditioning can make the air dry and worsen eye strain.
For more information
Royal Society of Ophthalmology – Understanding Dry Eye
Look after your eyes
- Stop smoking – Smokers are far more likely to develop visual loss from age-related macular degeneration than non-smokers.
- Wear sunglasses – Protect your eyes from U/V light. Never look directly at the sun. Sunlight exposure may be related to the development of cataracts.
When working at the computer
- Sit correctly at the computer – Follow ergonomic tips to ensure your chair and computer are properly adjusted. You should sit with the screen about one arm’s length away, and your eyes levels with the top of the screen or just below. Don’t sit staring up at the screen or this will cause pain in your neck. You may need to adjust your chair and the height of your seat.
- Enlarge the computer text – Adjust the screen so the letters are the right size for you to read them easily. This avoids having to squint.
- Reduce the glare – By adjusting the brightness on your computer screen as needed.
- The 20/20/20 Rule – Practise looking away from the computer screen at something in the distance, at least 20 feet away, every 20 minutes, for at least 20 seconds.
- Consider omega-3 supplements – In one 2015 randomised controlled study, a group of volunteers with dry eye took either two capsules per day of omega-3 fatty acids each containing 180mg eicosapentaenoic acid (EPA) and 120mg docosahexaenoic acid (DHA), or a placebo containing olive oil. At 3 months, the omega-3 group reported significantly improved dry eye symptoms compared to those who took the placebo.
- If things are not improving – See your GP. Always take care of your eyes. If symptoms are troublesome and simple measures have not helped. It’s time to ask your doctor for help.
Your eyes are your vision are vitally important for good health. We can’t do without digital screens in this modern age, but we can take steps to reduce DES. These tips have helped me, and I hope they will also help you.
For more information
- Patient – Is your office hurting your eyes?
- Moorfields Private Eye Hospital – 10 steps for digital eye strain relief
- BMJ Open Ophthalmology, April 2018 – Digital eye strain: prevalence, measurement and amelioration
Editor's Recommended Articles
Must Read >> Caring for your eyes whilst working from home
Must Read >> The impact of remote learning on your child’s vision