Eyesight issues during lockdown
It’s been suggested that the blue light emitted by digital devices could be harmful to your eyes. And these concerns have been raised even more during the pandemic. One in three people in the UK have reported problems with their eyesight because of spending more time on screens during lockdown. As people have adjusted to new ways of communicating, working and studying via screens, we’ve seen a rise in the popularity of blue light glasses.
What is blue light?
Sunlight has many types of coloured light, each with a different wavelength and energy level. When all the colours are combined, it creates sunlight, or ‘white light’. Blue light is one type within this light spectrum – it has a short wavelength and high energy levels.
Blue light comes from the sun, but also from manmade sources, such as computers, tablets and other digital screens. The amount of time spent on digital devices and how close they’re held to your eyes has caused some concern about blue light and eye health.
Because blue light has a short wavelength, it can penetrate your eyes and reach your retina easier than other coloured light. Your retina is a thin layer of tissue that lines the back of your eye. Some experts have suggested that too much exposure to blue light can damage the light-sensitive cells in your retina.
Although screens do emit blue light, research has found that the level is significantly lower than that from natural daylight. This suggests that blue light damage to your eyes from digital screens is likely to be very little.
What are blue light glasses?
Blue light glasses (sometimes called blue light blocking glasses) contain lenses that filter blue light rays. They help reduce the amount of blue light that reaches your eyes. You don’t need to wear prescription glasses to use blue light ones. You can buy them online or in a shop without a prescription.
Do blue light glasses work?
Blue light glasses are effective at reducing the amount of blue light that enter your eyes. But currently, there’s no research to suggest they can protect or improve the health of your eyes.
Do blue light glasses reduce or prevent digital eye strain (DES)?
There’s not enough evidence to suggest that blue light causes digital eye strain (DES). DES and related eye issues are linked to how you use your digital devices – not the blue light coming from the screen.
If you spend too long staring at a screen, your eyes can become fatigued. Sitting too close to a screen can strain your eye muscles as they constantly shift and change focus.
Top tips to avoid digital eye strain (DES)
Reducing how much time you spend on screens and taking regular breaks is key to reducing and preventing DES. Here are my top tips to avoid DES.
- Follow the 20-20-20 rule. For every 20 minutes using a screen, look at something 20 feet away for 20 seconds.
- Blink regularly.
- Make sure your screen is between 40 to 75cm away, and eye level (looking up strains your eyes, but looking down will strain your neck and back).
- Make your text size bigger to reduce the amount of work your eyes need to do to focus.
- Make sure images and text on digital devices are sharp and in focus.
- Make sure there’s no flickering on your screen.
- Adjust the brightness of your device to suit your environment. For example, if you’re using a tablet in low light, reduce the brightness of your screen. Many devices have a ‘night-time mode’ you can switch it too.
- Make sure your screen surfaces are clean.
- Reduce any glare from sunlight or artificial light.
- Use eye drops (artificial tears) if your eyes get dry.
- Have an eye test every two years, even if you have no problems with your vision. Go for a test sooner if you notice changes in your vision or are having any problems.
- If you’re prescribed glasses, make sure you wear them when advised to.
Blue light glasses and sleep
Blue light is a short wavelength type of light. It can promote alertness and performance and is the most important regulator of your circadian rhythm (your sleep-wake cycle).
Another argument in favour of blue light glasses is that they can help you sleep better at night. Some studies show a link between evening using your digital devices in the evening and not getting enough good-quality sleep.
It’s suggested that blue light from digital devices can reduce how much melatonin your body makes. This is a natural hormone that helps control your sleep cycle. A 2017 study found that participants who wore blue light glasses showed around a 58% increase in their night-time melatonin levels.
Tips for using technology at night
- Avoid computers, smartphones and other blue light-emitting devices in the hours leading up to bedtime.
- Make your bedroom a screen-free zone. Enjoy reading or listening to a podcast to wind-down instead.
- Switch devices to night-time mode. This reduces the brightness and amount of blue light from the device.
- Consider wearing blue light glasses, especially if you have to work or study in the evening.
Despite the rising popularity of blue light glasses, there’s no conclusive evidence that they can reduce or prevent eye strain. But reducing the amount of blue light that penetrates your eyes may help improve your sleep.
Most importantly, there’s no research to suggest that blue light glasses cause any harm. Because of this, they may be something you choose to wear, or buy for your children. Above all, reduce the amount of time you and your family spend on screens and take regular breaks when using them.