Uv Light - All About Vision

UV light is bad news for your skin. And it’s not exactly good news for your eyesight. But what is UV light and why is it dangerous? 

The answers to these questions will help you understand the risks of UV light. Read on for tips on saving your skin and preserving your eyesight.   

What does UV mean? 

UV is short for ultraviolet. In a crayon, violet is a shade of purple. In the scientific world, violet is a wavelength of light that the human brain interprets as purple. Thus, ultraviolet is an extra-high version of the violet wavelength.    

Wavelengths measure the distance between the top of a wave and the top of the next wave. Waves happen at the beach when waves crash into the shore. The wavelength is the distance between the wave that’s hitting the shore and the wave right behind it. 

And, of course, waves happen in space. Sunlight moves in waves traveling at the speed of light (186,000 miles per second, or 670 million miles per hour). All light waves are not the same: Different colors of light have different wavelengths as measured on the electromagnetic (EM) spectrum. 

What is the electromagnetic spectrum?

The EM spectrum measures energy by wavelength. The shortest wavelengths are at one end, middle wavelengths are in the center and the longest wavelengths are at the other end. 

The electromagnetic waves with the shortest wavelengths carry the most energy, and those with the longest wavelengths carry the least energy. High-energy wavelengths include gamma rays and X-rays. Low-energy wavelengths include radio waves and microwaves. 

The human vision system sees only a tiny fraction of the EM spectrum. We call this fraction the visible light spectrum, which is in the center of the electromagnetic spectrum.