Electromagnetic Spectrum and photoaging

Today I’m writing about the electromagnetic spectrum.

Now you can be forgiven for thinking this is an unusual topic to be writing about, especially for a skin care site.

But in fact it is really important, if you are keen to understand how radiation affects our skin.

The Electromagnetic Spectrum

Our eyes are naturally designed to detect visible radiation, or visible light waves.

This is the type of light or radiation that penetrates our atmosphere, and can be detected on the Earth’s surface by the naked eye.

Some radiation we can see, but there are many types of radiation that we actually can’t see, this is referred to as the electromagnetic spectrum, which is made up of 8 different parts:

  • Radio Waves
  • Microwaves
  • Terahertz Radiation
  • Infrared Light (IR)
  • Visible Light
  • Ultraviolet Rays (UV)
  • X-Rays
  • Gamma Rays

All of this radiation travels at the speed of light…

The only difference between these types of radiation, is their wavelength (which increases) or frequency (which decreases).

  • Radio
  • Visible light
  • Some infra red
  • A tiny amount of ultraviolet radiation

This is the radiation that reaches us on the Earth’s surface, from outer space.

We are lucky that the atmosphere helps to block out all the rest which is deadly.

UV: Radiation is part of this electromagnetic sphere that reaches the earth from the sun.

The rays that affect our skin


UVA accounts for 95% of radiation reaching the earth’s surface, we are exposed to masses of this through our lifetime.
Not only does UVA play a major role in photo aging, but it also damages keratinocytes in the basal layer, which is where most skin cancers occur.


UVB causes skin reddening and sunburn, and also plays a role in the development of skin cancer and photo aging.


UVC is a shorter ray, no conclusive research to date has found that UVC can penetrate our skin. However there is a school of thought that suggests UVC can be damaging from fluorescent light bulbs.

Follow the link, to find out about Infrared Rays and the skin.

Time of day also affects levels of UVB and UVA

  • UVB rays are only present when the sun is high between 12 and 2pm
  • UVA rays are closer in wavelengths, so are present all day long, in fact every day all year round
  • UV radiation also increases with altitude, for every 300 meters you ascend there is a 4% increase

Apologies for going all sciencey on you, but hopefully now, you begin to get more of an idea, of how these damaging rays are formed.

Join us here to find out more facts about sun damaged skin.

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