The majority of an average workday can be spent using a computer. During the COVID-19 pandemic, our screen time has increased even more with video calling, online meetings, and webinars1 becoming a common feature of the workday. It can take a toll on our eye muscles and and it has been shown it can affects our productivity2. BETTER VISION gives tips and information on glasses for computers, and preventive measures for computer vision syndrome (CVS).
The term computer vision syndrome (CVS) is used to describe problems that result from prolonged computer, tablet, e-reader and smartphone use. It’s also referred to as digital eye strain (DES) because the symptoms are not limited to time spent at computers only, but any digital device.
When you use any digital device, it places a unique demand on your eyes, different to any other visual activity. You have to either focus at a screen for long periods of time, or frequently change your gaze between a device such as your phone or a tablet and the environment around you. This can place strain on the eyes, making it harder to accommodate (changing your focus between different distances). For this reason, people who use digital devices a lot can experience vision- and posture-related issues.
According to the American Optometric Association, the most common symptoms of DES are eye achestrain, headaches, blurred vision, and dry or burning eyes, as well as neck and shoulder pain.3 If you’re over 40 years of age, natural changes in accommodation could also result in the gradual loss of the ability to maintain clear vision on near objects (presbyopia), which can cause visual discomfort and exacerbate DES symptoms.
With more and more people working from home, having a proper, dedicated space for a home office has become very important. An ergonomic sitting posture at the screen and the right glasses prescription can improve comfort and vision at a computer work station.
Chair and desk
A new chair or even just an adjustment of the chair settings can help to make work less straining. Make sure that the natural curve of your lower back is supported by your chair (lumbar support), so you can comfortably keep your upper back straight.
As a rule of thumb, you should be able to fit a fist between the top of your thighs and the bottom of your desk. If there’s no space between your legs and the desk, your desk is too low and you should either adjust your chair or make the desk a little higher by propping it up on blocks or books. If there’s too much space between the desk and your legs, adjust the chair so it’s a little higher.
Make sure that your feet are flat on the ground, and that your legs form a 90º angle with your body. If you’re short, try a footrest to see if it improves your sitting position.
Screen and keyboard
Make sure that your screen has the highest possible refresh rate and image stability. Adjust your monitor so that the picture is rich in contrast and sharp. Also adjust the font size so that you can read the text easily and comfortably.
The top of the screen should be slightly below horizontal eye level, and about 50 cm away from your eyes. Test the distance so it’s more or less an arm’s length.
Getting the right distance and height can be a bit harder with laptops. Making use of peripheral devices that you can plug into your laptop, such as a mouse, keyboard and monitor, can help to improve your comfort. There are also various ergonomic laptop stands that can be adjusted to a comfortable reading and typing height, and a lot of these can also fold flat so you can take it with you wherever you go.
When setting up your keyboard, you should be able to rest your forearms or elbows on your chair armrests while typing, without having to hunch your shoulders. The same goes for using a trackpad or mouse.
If you’re experiencing symptoms of DES, it’s important to go for an eye test, or update your current glasses prescription. It’s possible that you simply have an uncorrected glasses prescription (refractive error), and the right lenses may correct this and improve your symptoms.
y.You may find that a new pair of glasses can actually improve the way you work, as research shows that uncorrected refractive errors can have a negative an impact on economic productivity.4
When your regular prescription or reading glasses don’t improve CVS, it may be time to consider computer glasses; this is especially so for those aged 40 years and over.
If you are over 40 years of age, single vision or progressive lenses may not be optimised for your office work. Reading glasses enable optimum vision that may be too close for computer work. Progressive lenses tend to have a small area for you to look through in the lower part of the lens, so you will unnaturally tilt your head upwards to see the screen. If you wear these types of lenses for office work, chances are that you’re sitting in an unnatural position, leading to headache and muscle tension.
Your eyes need support in the intermediate zone when you work at a desk on a daily basis. This refers to the distance more or less where your screen is positioned. It’s a little further away than near vision (a book or checking your phone), and closer than distance vision (looking at something far in the distance or driving). When we focus at this intermediate distance our eyes have to converge and this can be quite tiring for the eye muscles if sustained for extended periods of time.
Computer glasses, also known as office lenses, are optimised to correct refractive errors for the intermediate viewing zone whilst offering a wide field of view and a more comfortable viewing position for your eyes.
What to look for when buying computer glasses
- How will you use your computer glasses?
As you will see here, there are different types of computer glasses. It’s important to discuss with your eyecare professional exactly what you will be using your glasses for, so that your prescription and lens choice can be tailored to meet your needs.
- Refraction, fitting and centration
The more exact these measurements are, the faster you will adapt to your new lenses and the more comfortable your vision will be.
- Anti-glare coating
Anti-glare or anti-reflective (AR) coatings are applied to the lenses to eliminate irritating reflections from the front and back surfaces of the lenses. Vision challenges like glare or reflections can decrease the wearer’s visual comfort and may contribute to symptoms of CVS. These coatings will leave a residual green or blue hue on the lens surface. Discuss your options of anti-reflection coatings for computers with your eyecare professional.
Blue light filtering is a common feature of lenses designed to be used with digital devices. Some blue light filtering lenses produce a visible blue/purple reflex on the lens surface. This can be especially evident during video calls. If appearance is high on your list, look for lenses with in-material blue light filtering technology, rather than coated lenses. The blue light protection is incorporated into the lens itself, so visible reflections are minimised.
There are different types of lenses for computer glasses to choose from, depending on your visual requirements. If you are over 40 years of age, the mostly likely option you will need is an office lens, which can be tailored to your office set up.
Generally, there are three types of office setups:
- An indoor workstation with a computer, and some contact with other staff.
- An indoor workstation where the person predominantly reads a lot of printed material and looks at sketches (for example architects).
- An indoor office setup with a lot of contact with other staff and customers, as well as some computer work.
These lenses have a maximum distance for clear vision of up to one metre away from you. Compared to reading glasses, it will give you a significantly larger field of vision for a comfortable reading experience.
With this option, you will have clear vision for a distance of up to two metres away from you. This option is ideal for those who do prolonged computer work as well as and reading close up.
Comfortable vision ranges from a closeup reading distance to a typical room distance of up to four metres. This option is ideal if you work at a computer and interact with people that might be standing away from your desk, as you don’t have to take off your spectacles to see them clearly when getting up from your desk and walking around.
Visible light is the portion of the electromagnetic spectrum that is visible to the human eye. A portion of this visible light falls in the blue/violet band and is described as high energy visible light (HEV). The sun is the brightest source of blue light. A part of the blue light spectrum is good for us during the daytime, as it boosts attention, mood and reaction time.
Modern digital devices such as smartphones, televisions, computer monitors, e-readers and tablets emit blue light. Even energy saving LED bulbs emit blue light.
At night, overexposure to blue light can affect the body’s circadian rhythm, leading to sleeplessness and fatigue.
As we grow older, less blue light passes through the eye to the retina – only 20% of blue light passes to the retina by the time we reach the age of about 60 years . However, if you spend a lot of time working on digital devices, you could expose your eyes to more blue light than you realise. Too much night-time blue light exposure can also make it difficult to sleep and exacerbate patterns of insomnia.
It’s important to note that not all computer glasses are blue light blocking glasses. Spectacles for computers are simply designed to improve visual comfort in the intermediate zone, and it doesn’t necessarily feature blue light protective qualities.
However, you can customise your computer lenses or any other glasses lenses with a specialised blue light coating. Such coatings are applied to lenses and include a blue light filter which lessens the transmission of blue light through the lens and into your eyes. This can improve your visual comfort, without losing out on its beneficial effects.
If you don’t have a prescription for a refractive error, you can still wear anti blue light glasses. Your eye care professional will be able to advise you on your options.
- Take breaks
Get up from your desk whenever you get a chance and go for a quick walk. Fetch a glass of water or make a cup of coffee or tea, just to ensure you give your eyes a rest and that your body doesn’t remain in the same position for too long - remember not too drink too much caffeine though as this can dehydrate you!
- Rest your eyes
The 20-20-20 rule applies here. Every 20 minutes, look into the distance at least 20 feet (6 metres) away, for at least 20 seconds. This will ensure less eyestrain from focusing in the intermediate zone for too long.
- Blink often
We tend to forget to blink, subconsciously, when working on digital devices. Blink deep and hard whenever you remember to, and when you take breaks also make a conscious effort to blink. This will lubricate your eyes and improve symptoms of dry eyes. Keeping yourself hydrated by drinking water will help you too.
- Take care when setting up your workstation
Follow these guidelines when setting up your workstation.
- Exercise and stretch
Try to exercise or walk at least three times a week, and stretch your sore and tired muscles throughout the day. Add on a 10-minute stretching session after a particularly long day’s work.
Speak to your eyecare professional if you perceive increased eye strain, dry eyes and blurry vision from using digital devices.