To begin with I’d like to ask you a question – do you know what blue light blocking glasses are and what do they do? I’m sure you all know the answer by now. These are special spectacle lenses that apparently block blue light–a major contributor to eye strain and several other eye problems—emitted from digital screens. Since blue light also occurs naturally in sunlight, signaling that it’s time to wake up, digital blue light tricks our brains into thinking it’s time to wake up. The result is pretty obvious – you’re unable to sleep. Even though your device may have a blue light filter on, it’s never 100 percent reliable. Additionally, if you’re using blue glasses are you sure it blocks 100 percent of the blue light emitted from your devices, or do you have blind faith in the claims made by brands? Blue light filter eyeglasses are the IT accessory of the season and everyone wants one, but not all blue lenses block those harmful rays. It’s more of a marketing strategy we fall for, but not anymore! Here are some quick tests to see if your blue glasses really work.
Many electronic displays utilize a technology called Liquid Crystal Display (LCD) to create the color images on the screen. To simplify, the screens are composed of many pixel panels. Each pixel has three subpixels which are composed of red, green, and blue. Through control of the voltage applied, each pixel can be switched on or off, or have its intensity-modulated. This variation produces the range of colors that you see on a screen.
We perceive colors through certain specialized cells present in our eyes known as cones. These cones are photoreceptors that are sensitive to color. A human eye has approximately six to seven million cones that are concentrated at the back of the retina. And when light reaches your eye, a specific type of cone – either red, green or blue will fire, depending on the wavelength of the light. The visual lens cortex within the brain obtains the message and forms an imaginary picture of the image. Simultaneously, the brain also uses the additive color method to form secondary colors. For example, when we see an object that’s yellow, only the red and green cones are stimulated because red + green = yellow.
One of the easiest tests that you can try at home is the reflection rest. For this, all you have to do is to pop your computer glasses on and see what color reflects off the lenses by standing in front of a mirror.If you see blue light reflecting off them then it’s a sign that they are filtering blue light. But if the reflection is violet or purple, then your lenses aren’t filtering blue light effectively. This is a basic test you can do at home to test the effectiveness of your blue light glasses. If needed you can also do this test before purchasing your computer glasses.
Another way to test your blue light glasses is by using the RGB circle test. For that, you will need to look at this image.If you’re using normal prescription lenses without any blue light filter the two images shown above will appear differently. Now if you try looking at these images with your blue light filtering eyewear, both images will appear almost identical.Let’s do this step-by-step:
1)Wear your blue light glasses and look at the image carefully
2)If your glasses are able to filter blue light, the B section will appear black and the G section should darken considerably. This demonstrates that your blue light glasses are not only filtering blue light but some green light, as well, which is very important when using your glasses after sunset.
So, there you have it, two simple and easy ways to test your blue light glasses and see for yourself if they actually work or not.
Visit our Westpoint Optcal to Book an eye exam contact us: Brampton West: 905-488-1626 or Brampton East: 647-948-8581.