The sun sends energy to Earth in a few different ways: visible light that you can see, infrared radiation that you feel as heat, and rays of UV radiation that you can’t see or feel.
There are three types of UV rays:
- Ultraviolet A rays (UVA)
- The atmosphere does little to shield these rays—most UVA radiation reaches Earth’s surface.
- UVA rays cause skin aging and eye damage, and can lower your body’s ability to fight off illness. UVA rays also contribute to the risk of skin cancer.
- Ultraviolet B rays (UVB)
- The Earth’s atmosphere shields us from most UVB rays—the amount of UVB rays that reach the Earth’s surface depends on latitude, altitude, time of year and other factors.
- Ultraviolet C rays (UVC) do not reach the Earth’s surface because they are completely absorbed by the atmosphere.
The ozone layer protects us from harmful ultraviolet rays of the sun.