DIFFERENT TYPES OF UV RAYS
What THE DIFFERENCE BETWEEN UVA AND UVB?
So, which type of UV radiation is most harmful? UVB rays are classed as being between 290 and 320mn. They represent 5% of the rays reaching the Earth, are more energetic and don’t penetrate as deeply as their UVA counterparts. For this reason, UVB rays are responsible for causing sunburn.
On the other hand, UVA rays range from 320 to 400nm. They represent 95% of rays that reach us. They are less energetic, but penetrate deeper and even reach the dermis. We don't feel these rays, but when it comes to our skin, they are, in fact, the most damaging. We are also exposed to roughly 20 times more UVA rays than UVB. This means that it’s particularly important to find the best UV protection.
WHAT ARE ULTRA-LONG UVA RAYS?
AND WHY ARE THEY THE MOST INSIDIOUS?
As we now know, when considering the different types of UV rays, it is UVA rays that penetrate deeper into the skin. They’re present all year round – even on rainy days and throughout winter. They can even pass through clouds and reach our skin through windows. When choosing your UV protection, it’s also important to note that within the UVA range, there is a special type of ray called ultra-long UVA, which ranges from 380 to 400mn. These ultra-long UVA rays represent 30% of the total UV light reaching our skin. The fact that they penetrate the deepest means that they cause several types of biological damage, making them the most insidious.
HOW DO LONG UVA RAYS DAMAGE THE SKIN?
LONG AND SHORT TERM UV RADIATION EFFECTS
Long UVA rays cause severe sun damage by fundamentally altering the skin structure and biology. They reach both the epidermis and dermis and can lead to DNA damage, which has several short and long term effects on the skin.As well as causing oxidative stress, long UVA can lead to pigmentation disorders due to changes in melanin production. Long UVA damage cause fibroblast degradation, resulting in wrinkles, sagging and loss of skin volume. By decreasing the number of important cells called Langerhans cells, it can also bring about photo-immunosuppression – or a weakening of the skin’s immune system.
We see the visible effects of long UVA sun damage on the skin surface in a number of ways: We may develop a UV allergy, hyperpigmentation, photosensitivity and the signs of ageing. In the worse cases, it can also lead to skin cancer.
So, how do we go about protecting our skin with a high UVA sunscreen?
WHY IS MEXORYL 400 SUCH A BIG REVOLUTION IN SUNCARE?
After 10 years of research and 65 studies, the new Mexoryl 400 filter has 25 patents and is the only filter to protect against long UVA skin damage. As the biggest revolution in suncare for 30 years, this pioneering filter is a new daily spf essential in protecting the skin against the most insidious ultra-long UVA rays. These rays, which range from 380 to 400nm, represent 30% of all UV rays reaching our skin each day.Following in the footsteps of La Roche-Posay Invisible fluid, the Mexoryl 400 filter can be found in new UVMUNE 400 Invisible Fluid spf50+, which are clinically proven to deliver broader protection by defending the skin against ultra-long UVA rays.