UVA vs. UVB — What’s the Difference & How They Affect Your Skin

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Everybody says you should protect from ultraviolet radiation, but it’s challenging to comply if you don’t understand what is all about. Here is the right place to start as this post covers all you need to know, from the differences between UV rays, how they affect the skin, plus some tips for limiting sun damage. Understanding the basics of UV radiation is the first and most important step in learning how to protect yourself against photoaging, sunburns, skin cancer, and even eye damage.

What is UV light?

UV is a type of energy produced by the sun and some artificial sources such as tanning beds. According to the American Cancer Society, a few factors influence the strength of the UV rays reaching the ground. UV rays are strongest between 10 AM and 4 PM and more harmful during the spring and summer months. UV can also penetrate clouds and windows and can bounce off surfaces like water, sand, snow, or even grass that’s why we need sunscreen all year round.

Two types of UV rays reach the ground: ultraviolet A-rays (UVA) and ultraviolet B-rays (UVB), each in a different amount. Approximately 95% of the sun’s UV rays that reach us are UVA, while 5% are UVB rays.

UVA – Associated with skin aging

UVA rays may have the lowest energy level, but they still contribute to premature skin aging and skin cancer development. This is why lately, brands began adding ingredients in sunscreens to protect you from both UVA and UVB. While UVA rays are lightly less intense than UVB, they penetrate the skin more deeply and can cause cell damage. The skin tries to prevent further damage by darkening, resulting in a tan, but no tan is healthy. Over time, UVA exposure leads to photoaging, defined by wrinkles, dark spots, and loss of firmness and elasticity.

Research found that the visibly damaging effects of UVA radiation only appear after years of exposure. They also show that skin sensitivity to UV light is linked to the skin phototype, meaning light-colored skin is more sensitive than dark-colored skin.

UVB – Associated with skin burning

UVB rays are the ones responsible for producing sunburn, playing the greatest role in causing skin cancer because they penetrate and damage the outermost layer of the skin. Somehow it’s good news that only 5% of them reach the ground. But remember that UVB rays can damage your skin all-year-round, especially at high altitudes or on reflective surfaces (snow, ice). On the other hand, UVB rays can be filtered, and they don’t penetrate glass.

How to reduce UV damage


Antioxidants are great in protecting against free radicals, UV included. Why? Because UV exposure causes oxidative stress and antioxidants inhibit damage induced by oxidation. Studies confirmed that exposure to UV rays leads to the oxidation of cells that could be prevented by prior antioxidant treatment. As far as skincare is concerned, vitamin C is one of the best antioxidants because not only shields the skin against free radical damage but can increase collagen production. Oh, and it works even better when paired with vitamin E, boosting each other’s antioxidant power.


UV exposure can also lead to a deficiency of vitamin A, resulting in cell damage. Tretinoin is the active form of vitamin A, and it reduces photoaging effects. Studies have found that topical tretinoin combined with sunscreen is a god-sent for sun-damaged skin. You can also use retinol, which is an OTC form of tretinoin, less powerful.

How to protect against UV rays

First, try to stay in the shade or indoors, especially between 10 AM and 4 PM. Say no to UV tanning beds. Instead, find a product that tans your skin without the need for exposure to sunlight, such as a tanning lotion. And if it’s organic, you hit it big! Every time you go out, 30 minutes before, use a broad-spectrum (UVA and UVB) sunscreen. If you have to stay outdoors for extended amounts of time, use sunscreen with at least SPF 30. Always reapply every two hours if you’re swimming or sweating excessively. 

Clothing is a great barrier against the sun’s ultraviolet rays. Many fabrics offer high-tech protection and breathability at the same time. The more skin you cover, the better it is. Also, a hat with a wide brim (3 inches or more) helps a lot because it shades your face, ears, and neck. And remember, the sunglasses you wear should block UV — otherwise, your eyes and skin around them are not protected.

Who wrote this?
Ana Vasilescu
Ana Vasilescu
Ana is a sociologist and feminist with a shared passion for literature, psychology, and skincare, the combo that made her determined to start Women's Concepts. With over five years of experience in dermatological research, she has now become a certified skincare consultant keen to convince others of the importance of a diligent routine. Her close relationships with dermatologists around the globe, along with years of researching, analyzing studies, and hand-testing products on a daily basis, made Ana one of the best persons you can get advice from.
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