Blue light glasses have a filter which blocks or absorbs the short wavelength light that can make it harder to fall asleep at night. They might also help alleviate eye strain for people who spend a lot of time in front of the computer or on devices.
Anyone can wear blue light glasses – even if you don’t need reading glasses. A blue light filter can be easily added when you purchase your spectacles.
Blue light is a high energy, short wavelength light that is emitted by the sun during the day. It also radiates from smart phones, tablets, computers, televisions, electronic devices and even fluorescent or LED (energy saving) lights.
Short and long wavelength light can be explained by thinking of a rainbow. A rainbow forms when light coming from the sun is split by the water in the air and shows you the longer and shorter wavelength lights as different colours. Short wavelength lights are the highest intensity and affect our bodies the most. Blue light is the strongest of the short wavelength lights. It hits the back of our eyes (the retina) and tells the body it’s daytime – so we should be awake and alert.
Exposure to blue light during the day is normal and perfectly healthy, but exposure to blue light from devices at night can keep you awake.
When the sun goes down our body starts producing melatonin (the natural hormone that makes you sleepy). Devices like smart phones and tablets are a potent artificial source of blue light and using them at night can confuse our bodies. Blue light emitted from devices can stop or slow the release of melatonin making it harder for you to fall asleep.
If you use a smart phone, tablet or digital device at night, as many of us do, wearing blue light glasses might improve your sleep. The evening is a particularly important time to minimise your exposure to blue light, so your body produces enough melatonin to make you feel tired and have a good night’s sleep.
It’s a good idea to avoid looking at a smart phone, computer or tablet for two to three hours before bed to ensure it doesn’t interfere with your sleep. Alternatively, you could slip on a pair of blue light glasses to minimise your exposure.
It’s important to remember blue light glasses aren’t designed to be worn all the time. Exposure to natural blue light from the sun is normal and can make you feel energised. It’s prolonged exposure to artificial light from screens that can impact our sleep.