What Is The Difference Between UVA and UVB Rays

When it comes to UV rays, they can harm our skin. Premature aging and skin cancer are two of the major side effects of too much sun, called actinic photodamage.

What you might not know, though, is the difference between the two main types of rays,

UVA and UVB, and how they affect your skin. Understanding this can help you better protect your skin, so keep reading to learn more.

This will you when you are picking out your sunscreen for these hot summer months.


UV Rays: The Basics

There are two different types of sun rays: ultraviolet A (UVA, or long wave) and ultraviolet B (UVB, or short wave), according to the Skin Cancer Foundation. They both cause skin cancer, eye damage, and premature aging in the form of wrinkles, fine lines and brown spots.  


UVA and UVB Rays: The Breakdown

UVA rays account for 95% of the rays we are exposed to. They’re always present — even on cloudy days — and can penetrate through glass like windows. They reach deep into the skin, which can cause an immediate tanning effect and are responsible for causing signs of Aging Think UVA Aging), such as wrinkles and loss of elasticity, to form. UVA rays can also contribute to the development of skin cancer. 


Most UVB rays are filtered by our atmosphere, but they are definitely harmful on sunny days and/or at higher altitudes. UVB rays cause surface-level damage, quickly burning and gradually tanning the skin, according to the World Health Organization. These rays play a bigger role in the development of melanoma or other forms of skin cancer. Think of UVB as those rays that cause sun Burns (B for Burns).


What Are UVC Rays?

There’s a third type of radiation that’s stronger still: UVC rays. The good news these don’t typically penetrate the ozone layer to reach our skin. So you won't find these on sunscreen labels and that is ok.


How to Protect Against UVA and UVB Rays

Our understanding of UVB and UVA rays is constantly evolving. This is why it’s important to protect yourself by always wearing broad-spectrum sunscreen, which protects against both types of rays. Look for the words Broad Spectrum Coverage on the label of your sunscreen. You need to wear sunscreen even when it is cloudy outside or when you are indoors. The best sunscreen is the one you use daily!

© 2020 HoushmandMD Dermatology

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Disclaimer: This site only provides information about dermatology and this information is not meant to be taken as medical advice. For more information about dermatology, contact Dr. Houshmand

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