High Energy Visible Light (HEV Light) is all around us. It’s part of the light we can see. It’s been around for as long as UV rays, but while much has been written about their effect on skin, the molecular and visible effect of HEV Light on skin is a more recent discovery. Research has proven that HEV Light influences skin condition and can cause skin to age prematurely. In this article we examine the effects HEV Light has on skin, put it into context alongside UVA and UVB rays and consider how best to protect skin from photoageing (premature skin ageing caused by the sun).
What is HEV Light and why do we need to protect skin from it?
Introducing HEV Light
What is HEV Light?
The sunlight spectrum consists of UV, visible and infrared light. 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 (UV and Infrared Light are both invisible).
The blue/violet band of this visible spectrum has a particularly high energy level and is known as High Energy Visible Light. This is often abbreviated to HEV Light or HEVL.
How does HEV Light compare to UV rays?
Light is measured in wavelengths, the units of which are nanometers (nm) and millimetres (mm). Visible light has a wavelength range in the region of 400 to 760nm, with HEV light falling somewhere between the 400-500nm mark. UV light has a shorter wavelength (of between 290 and 400nm) though UVA has longer wavelengths than UVB.
The vast majority of skin damage caused by the sun comes from UV rays and protecting skin from UV should remain the priority when caring for skin in the sun.
HEV Light and UV rays affect skin differently
- UVB rays are responsible for sunburn. HEV Light has not been associated with sunburn.
- UVB rays and, to a lesser extent, UVA rays have been linked to DNA damage which can cause skin cancer. HEV Light is not associated with skin cancer.
- Both UVA rays and HEV Light can cause skin to age prematurely (photoage).
- UVA rays are the primary cause of sun allergies. UVB rays can also cause sun allergies, but to a lesser extent.
- UVA, UVB and HEV Light can induce hyperpigmentation and may contribute to conditions such as age spots (also known as sun spots) and melasma.
HEV Light and premature skin ageing
Like UVA rays, HEV Light generates free radicals (also known as ROS – Reactive Oxygen Species). These free radicals cause skin cells to produce enzymes that break down the collagen and elastin that give skin its plump, youthful appearance. This process is often called oxidative stress and it’s what causes skin to photoage (age prematurely as a result of sun exposure).
Ageing is, of course, an entirely natural process, but when skin ages prematurely it may start to sag and develop deep wrinkles before its time.
HEV Light and uneven pigmentation
melasma, the pigmentation condition that leads to the sun spots often seen in darker skins1.
1. Source: VIS Study, 2013
Protecting skin from the oxidative stress caused by HEV Light
It’s important to remember that the sun’s rays affect your skin even when the weather is cloudy and overcast. Sun care should not be restricted to those days when the sun is at its hottest, but should form part of your daily skincare routine.
When choosing appropriate suncare products, the priority is still to give your skin the very best protection against UVA and UVB rays, but choosing products that also combat the oxidative stress caused also by HEV Light will further help to prevent photoageing and may reduce hyperpigmentation.
Many modern sun creams and lotions offer effective protection against UVA and UVB rays, but the chemicals and pigments used to filter UVA and UVB do not filter HEV Light. For this reason, we recommend that you look out for products that contain antioxidants that work against oxidative stress. Antioxidants Licochalcone A and Glycyrrhetinic Acid have been proven to work together to protect skin cells in the deeper epidermal layers from sun-induced damage.
Licochalcone A is a powerful antioxidant that neutralises the harmful free radicals that cause oxidative stress and accelerate skin ageing. As an ingredient from natural origin, it’s derived from the root of the Chinese Liquorice plant (Glycyrrhiza Glabra). Clinical and dermatological research has proven that sunscreens containing Licochalcone A offer effective and extended protection: from HEV Light in addition to UV.2 An effective anti-inflammatory, it also soothes irritated skin and reduces redness.
Glycyrrhetinic Acid supports skin’s own DNA repair mechanisms. Like Licochalcone A, it is a powerful antioxidant that derives from the root of the Chinese Liquorice plant. It also has anti-inflammatory and soothing properties.
In addition to these two active ingredients, there are ingredients that can help to alleviate the visual symptoms of sun-induced damage. Hyaluronic Acid, for example, is proven to boost skin moisturisation, plump skin from the inside out and reduce even deep wrinkles.
Licochalcone A, Glycyrrhetinic Acid and Hyaluronic Acid are the active ingredients in Eucerin Sun Fluid Anti-Age SPF30 and SPF50 which have been proven to offer reliable protection from UVA and UVB rays and to combat the oxidative stress caused by HEV Light. Both products help to prevent photoageing and reduce wrinkles.
2. Source: Chartité report, Protective efficacy of licochalcone A containing sunscreen in the high energy visible spectral range in vivo, March 2016.