It’s a sunny but chilly day, and you’re ready to hit the slopes or go for a wintry walk. You’ve bundled up in warm clothes, you’ve slathered sunscreen on your face, and you may have thrown on a pair of sunglasses to reduce glare and help you see bumps and dips in the blinding white snow. Or you’ve decided to pack your goggles to prevent snow from spraying you in the eye as you swish down a mountain.
But have you ever considered that your glasses or goggles could be as important for protecting your eyes from the sun’s harsh rays as sunscreen is for protecting your skin? Your eyes are as vulnerable as your skin to the harmful effects of ultraviolet (UV) radiation. And, like your skin, your eyes need protection—whether you’re hitting the slopes or walking to school.
You can’t apply a cream or spray to your eyes, so how can you protect them? The answer is with the right pair of glasses or goggles. So, you really do have an excuse to wear shades in the winter without looking pretentious. With cold-weather fashion finally catching up to science, you have plenty of frames to choose from. The question is: What types of eyewear should you look for?
Awash with Waves
To answer that question, it’s best to understand what you’re protecting your eyes from. You’ve probably heard of UV radiation, and that too much exposure is bad for your skin. But what is UV radiation exactly?
Let’s start by considering all of the radiation from the sun. The light emitted or radiated from the sun acts like both waves and particles carrying electromagnetic energy. The particles are called photons. The spectrum, or range of the waves, comprises the individual wavelengths and frequencies.
To understand these characteristics, think of ripples on the surface of a pond. The wavelength is the distance between one wave’s crest and the next. The frequency of the waves is defined as the number of complete waves or cycles that pass by a reference point during a specific time period.
Our eyes are sensitive to only a small portion of electromagnetic waves in a range that we call visible light. When all the wavelengths in the visible spectrum are mixed together, we see white light. Shine white light through a prism or view the light reflected off the back of a CD, and you’ll see the colors of the rainbow: red, orange, yellow, green, blue, indigo, and violet (a.k.a., Roy G. Biv, possibly the first art mnemonic you ever learned). This separation is called dispersion.