18th March 2021

During this pandemic many more people have been working extensively or exclusively from home, and for most this means longer and more frequent periods sat in front of a computer screen. Although this is, in many ways, a convenient way to work, there are drawbacks. One of these is the strain that prolonged screen use puts on our eyes.1

There are several factors which contribute to the detrimental effect on our eyes. Firstly, when we stare at a screen, our blink rate drops dramatically to about 30% of our normal blink rate.2 Blinking is important because it keeps the surface of the eye – the cornea and sclera – lubricated and prevents the eye from drying out in between blinks. The act of blinking squeezes out an oil, called meibomian lipids, from glands located along the lid margins and spreads it across the eye surface. This prevents the watery tear film from evaporating when the eyes are open. When we stare at a computer or device screen, our reduced blink rate allows the oil layer to break-up and consequently the tear film underneath evaporates.2,3 This can lead to a condition called digital eye strain (DES).1,2 

One aspect of DES is the development of symptoms related to ‘dry-eye’, which include burning sensations, irritation and tearing, redness, and ocular discomfort. Eyesight is affected, and eye surface damage can result if not managed or treated.2,3 

When we are using a computer, it is therefore important to make a conscious effort to blink more often and take regular breaks away from the screen.4

Another aspect of DES associated with extended screen use is eye strain caused by the need to focus on images that are relatively close to our face.1,2 Accommodation is the ability to change the shape of the lens in our eye to allow us to focus on objects at different distances.2 This is achieved using the small ciliary muscle inside the eye which is attached to the lens. When we stare at objects that are close to us for long periods, this muscle can become fatigued which we feel as eye strain.1,2,4 Symptoms can be eye ache and fatigue; headache, and blurred distance vision after computer use.2   

To avoid this type of eye strain associated with screen use, many organisations - including the American Academy of Ophthalmology (AAO) - recommend using the ‘20-20-20 rule’.5 This means that every 20 minutes when in front of a screen, you should look away at something at least 20 feet away for at least 20 seconds.5 In addition to this, the AAO suggest: reducing the brightness of your screen to match that of your surroundings; increasing screen contrast; and using a matte screen filter to reduce glare.5 

To summarise, when working on a computer or other device screen, here are five things you can try to keep your eyes healthy:

1. Blink more often 

2. Take regular breaks away from your screen

3. Use the 20-20-20 rule

4. Adjust your screen brightness and contrast

5. Try a matte screen filter

References

1. Hussaindeen JR, et al. Managing the myopia epidemic and digital eye strain post COVID-19 pandemic - What eye care practitioners need to know and implement? Indian J Ophthalmol 2020; 68(8): 1710-1712.

2. Sheppard AL, Wolffsohn JS. Digital eye strain: prevalence, measurement and amelioration. BMJ Open Ophthalmology 2018; 3: e000146.

3. Buckley RJ. Assessment and management of dry eye disease. Eye (Lond). 2018; 32(2): 200-203.

4. iHASCO. Preventing eyestrain at work. Available at:  https://www.ihasco.co.uk/blog/entry/107/prevent-eyestrain-at-work

5. Boyd K. Computers, Digital devices and eye strain. American Academy of Ophthalmology, 03 March, 2020. Available at: https://www.aao.org/eye-health/tips-prevention/computer-usage