Shedding light on blue light: How it can harm our skin, eyes

Most of us know how sunlight and air pollution affect our complexions and it is often assumed that we are safe from them when indoors.

But many scientists and dermatologists now contend that the typical office environment also poses a risk to our skin, as well as to our eyes.

The culprit is blue light, and we spend our work days and much of our lives exposed to high amounts of it.

More and more research has shown that blue light can generate free radicals with the potential to harm the skin, similar to the effects of UVA and UVB from sunlight.

Dermatologist Dr Joyce Lim from Joyce Lim Skin & Laser Clinic sheds more light on how and why blue light is so damaging.

What is blue light and what are the main ways we are exposed to it?

Blue light is visible light at one end of the visible light spectrum, with yellow and red light at the other end, and has the shortest but highest energy wavelength; hence the name "high energy visible light" (HEL).

The most common source of blue light is sunlight, while the most common artificial sources are the screens of our digital devices - phones, tablets, laptops and desktop computers.

It is also emitted from electronic devices like video game devices, and the new, low-energy fluorescent lighting (LED lights) used in offices.

How does blue light compare with other causes of photo damage such as UVA and UVB?

Both HEV and UV lights can cause skin damage and photo-ageing.

They both generate free radicals that may cause skin cells to produce enzymes that break down the collagen and elastin that give skin its plump, youthful appearance; a process called "oxidative stress", responsible for photo-ageing.

UVB rays only penetrate the outermost layers of skin, causing sunburn and playing a key role in the development of skin cancer. HEV rays have not been associated with such outcomes.

Both UV rays and HEV light can induce uneven skin pigmentation and may contribute to age or sun spots and melasma (a pigmentation condition resulting in brown to grey-brown patches that often affect people with darker skin).

The most important effect of blue light is on the eyes. The cornea and eye lens can filter out UV light but not blue light.

Hence, blue light is often associated with digital eye strain and retinal degeneration, which increases the risk of age-related macular degeneration.

Is blue light more damaging than UV rays?

No, it is not, but it remains an issue as we spend much more time exposed to HEV at close proximity in offices and homes, than under sunlight.

It poses the biggest threat to those with melasma - it may exacerbate existing melasma and trigger outbreaks.

How can we prevent or treat melasma?

There are now sunscreens available that contain HEV as well as UVA and UVB filters. Look for ingredients such as iron oxide in skincare products, as well as micronised titanium dioxide and zinc oxide.

Unless you already have existing conditions, blue light is unlikely to cause many issues other than some minor skin damage and eye strain.

The standard first-line treatment for a melasma outbreak is a topical medication (containing hydroquinone, tretinoin and fluocinolone acetonide), sometimes called a triple combination cream.

How can we reduce daily blue light exposure?

Use blue light filters and reduce the blue light component during evenings.

Some filters allow good blue light to pass through and filter off bad blue light.

Good blue light is important for our circadian cycle and health (alertness, cognitive function and well-being).

Blue light filters also protect our eyes from the risk of macular degeneration.

Some smart phones can be programmed to switch to a more yellow light at certain times in the day.