The dark side of blue light

Blue light from smartphones, laptops and tablets can affect us in numerous ways – but there are ways to dim the risks.

If you like to relax with Netflix on your tablet or work late on your computer, you’ll get a dose of blue light – a light emitted from not only the sun, but the electronic devices most of us use every day.

For some years, blue light has been linked to poor sleep, depression and some cancers.

And research now says blue light can also contribute to macular degeneration, an incurable condition that damages the eyes and can lead to blindness.

University of Toldeo scientists say blue light transforms molecules in the retina, so they become toxic and kill photoreceptor cells that we need for sight.

“We are being exposed to blue light continuously, and the eye’s cornea and lens cannot block or reflect it,” says researcher Dr Ajith Karunarathne.

“Blue light harms our vision by damaging the eye’s retina.”

Other studies have shown other negative effects of blue light.

Blue light’s links to cancer risk

This year, scientists at Barcelona Institute for Global Health linked blue light to increased risk of breast and prostate cancer.

They say artificial light, such as white LEDs that emit blue light, may increase the risk of breast cancer 1.5-fold and double the risk of prostate cancer.

They believe blue light upsets the body’s 24-hour clock, or circadian rhythm, which disrupts hormones that may trigger these cancers.

blue light risks

Blue light’s effects on sleep and depression

Exposure to blue light at night suppresses melatonin, a chemical that tells the body it’s time to sleep.

Lack of sleep has been linked to depression and increased risk of diabetes, as well as upsetting the metabolism.

The benefits of blue light

On the plus side, blue light therapy can be used to treat skin problems such as sun spots, acne and some scarring.

It can also be used treat seasonal affective disorder, by using a light box to mimic outdoor light. Researchers say this leads to chemical changes in the brain that improve mood.

How to protect against blue light

  • Wear sunglasses that filter UV and blue light
  • Avoid looking at bright screens two to three hours before bedtime
  • If you use an electronic device at night, install an app that filters blue light
  • Dim electronic devices and dim LED lighting at home by 50 per cent at night
  • If you’re buying a new mobile phone, look for one with a blue light filter

Written by Sarah Marinos.