UVA vs. UVB Rays

We all know that the sun can damage our skin, causing aging and even cancer, but most of us don't know how or why.

It can be difficult for you to know what to look for when you want to protect your skin, because it is easy to not know which UV rays are active. 

It is easy to know how to protect yourself if you know what you are protecting yourself from. The sun has two types of UV (ultraviolet) rays: 

1. UVA 

2. UVB 


The sun's rays range in length from 320 to 400 nanometers (billionths of a meter). You are almost never protected from exposure to UVA rays as they can pass through windows, light clothing and even your windshield, so if you are outside, you are exposing yourself to UVA rays. UVA rays cause aging. It is unlikely that UVB can cause sunburn, but UVA penetrates deep into the skin, causing wrinkles in the skin. Prolonged UVA exposure breaks down and reduces the collagen and elastin in our skin.

Collagen makes up 75% of our skin and is a fibrous protein in skin, cartilage, bones and other connective tissues. Along with elastin, it is responsible for the strength and elasticity of the skin, and its damage leads to wrinkles that accompany aging.

Elastin is a connective tissue protein that is flexible and allows the skin to regain its shape after stretching or contracting. When UVA rays damage these parts of our skin, our skin loses its elasticity and elasticity, causing wrinkles, sagging, sagging skin and ... aging! 

If that's not bad enough, research shows that UVA rays not only exacerbate the carcinogenic effects of UVB rays, but can also cause some skin cancers, including melanoma. UVB: 

Shorter wavelengths range from 290 to 320 nanometers.

UVB rays are more powerful than UVA in causing tanning. Therefore, these rays are considered as the main cause of skin cancer (basal and squamous cell carcinoma and melanoma).

Sometimes called "tanning rays", UVB rays stimulate melanocyte cells (located in the outermost layer of the skin) to produce brown melanin, producing a tan as a defense against UV rays. So even if it's a cloudy day and you're driving your car, the sun's harmful UV rays will see you. That's why it's important to always protect your skin with sunscreen and UV protective clothing (especially if you're working, playing or relaxing outdoors).