If you’ve recently been in the market for glasses, you may have noticed that things seem to have gotten a bit more complicated over the years. Many glasses are being labeled with initialisms like UV and HEV. But what do all these letters mean? UV? HEV? What are these labels on store-bought sunglasses or in your glasses manufacturer’s advertising actually referring to? How do they affect the practical everyday world? How are you protected? From what? By how much? We’re here to help answer these questions.
Explaining the Light Spectrum and “High Energy”
The light spectrum (as we understand it so far) goes from invisible infrared light to invisible ultraviolet (UV) light, in the middle between those two extremes is the visible spectrum which includes all the colours that people can see.
Therefore, what it means when glasses have “UV protection” is that theses glasses contain some type of material that either absorbs or reflects this highest energy part of the light spectrum (the ultraviolet range). This is really important because our sun emits light along the entire spectrum — not just visible light. And UV light, while necessary for vitamin D generation, can cause sun burns and skin cancer in excessive amounts. And yes, eyes can get sunburnt. Lenses with UV protection help to prevent this. When UV light hits your glasses, it’s reflected or absorbed into the UV protected glass.
What’s more rare is finding a pair of glasses that protects against the high energy light of the visible spectrum. This light has almost as much energy as UV, but it’s still visible to people. You may have heard of this high energy light referred to as “blue light,” and it’s emitted by the sun but also in the glow of computer screens and smartphones. During the day, some blue light isn’t a bad thing. It signals your brain that it’s day and that you should be awake and alert. But too much blue light can cause digital eye strain, and at night, it can prevent your brain from receiving the signals that it’s time to go to sleep.
What too much blue can mean for your sight long term…
Any type of light, whether visible or not, will affect our eyes, but which area of our eyes is affected depends on which frequencies of light we’re exposed to. Higher energy light (like blue light) affects the back of the eye which increases the risk of macular degeneration. Excessive exposure to UV light and blue light also increases your risk of cataracts at the front of the eye.
How can blue light be stopped?
In the same way that a coating on sunglasses captures the sun’s UV light, a different type of coating can be added to glasses to catch the blue light emitted from tablets, smartphones, and computer screens. A little blue light is fine, but reducing your exposure to this high energy light will help prevent macular degeneration.
At Doig Optometry, we’ve coined the phrase “High Energy Light Protection” or H.E.L.P. to describe all the things we do to protect your eyes from the damage that can come from high energy blue light. Getting High Energy Light Protection (H.E.L.P.) sets your glasses light years ahead from those who still do daily work on a computer screen without any protection. Glasses with H.E.L.P. will protect your eyes from macular degeneration, digital eyestrain, and make it easier to sleep at night.
Do your eyes need some H.E.L.P.? If you spend most of your time staring at a screen rather than the beach, you may want to swap out the sunnies for some hip H.E.L.P. shades. Get started by booking an appointment with Calgary’s Doig Optometry. Call us at (403) 333-3353 today!