Take a wander down the skincare aisle of any health and beauty retailer and you’ll be met with a bewildering array of creams and sprays, promising to protect you from various threats to your skin.

You might have noticed skincare companies claiming their products can protect you from the effects of blue light. If you hadn’t thought about blue light before, you’d be forgiven for worrying about whether you should be concerned.

First you need to understand what blue light is.

Visible light accounts for 50% of the sunlight spectrum and, as the name suggests, it’s the only part of light that can be detected by the human eye. The blue band of this visible spectrum has a particularly high energy level.

The longer the wavelength, the less energy it transmits. Blue light has very short, high energy waves.

Blue light is all around you. The sun emits blue light. So do fluorescent and incandescent light bulbs, mobile phones, computer screens and flat screen televisions.

What are the risks?

There is mounting evidence that blue light can have a harmful effect on the skin and eyes and disrupt the circadian rhythm (your internal clock). Typically, studies investigating the impact of sun radiation on the skin have focused on ultraviolet radiation, particularly UVB, which is responsible for sunburn. The most frequently reported effect of blue light exposure is a significant increase in reactive oxygen species (ROS), highly reactive chemicals formed from oxygen. Too much ROS can damage your DNA and key enzymes such as those responsible for DNA repair, increasing your risk of cancer.

Our research showed blue light can induce pigmentation (tanning) across skin types. While many people consider a deep tan a desirable trait, it is a marker of skin damage and ROS. Others researchers found skin tans from visible light (which includes blue light) had darker pigmentation that lasted longer compared to ultraviolet radiation exposure. Our studies also showed blue light can activate genes associated with inflammation and photoageing (skin damage). Several studies have proved typical sunscreens do not prevent blue and visible light damage.

While blue light appears to be less potent than ultraviolet radiation, this may be accounted for by the relatively larger amounts of blue light that reach the Earth. UVR accounts for around 5% of solar radiation in the UK at midday in the summer. Blue light makes up around three times more at 15%.

There are some beneficial effects of blue light. It has been used to treat skin conditions including eczema, it is widely used in photodynamic therapy, which is used to treat a range of skins conditions, from acne to cancer, and it boosts wound healing. But the harmful effects of blue light are likely to outweigh the positives for healthy people.