Within days of the Great Eclipse, many people are currently asking very important questions about solar eclipse safety, including, “Do solar eclipse glasses work?” The short answer is yes, they do – but there’s a caveat: you must absolutely ensure your solar eclipse glasses are legitimate. If they are, everything will be fine; but hey … let’s just say it’s not time to try to tinker with your own or take risks with a sketchy business. Your eyesight is literally at stake.
The OC register has a great explanation of both how the solar eclipse can damage your eyes and how solar eclipse glasses prevent this damage from happening. According to ROCK, if you look directly at a solar eclipse without the right shields, there are three different ways to tell bad news for your vision: first, visible light hits; then there are UVB rays, which can burn the outer cells of your cornea (besides being painful, it can cause blurred vision); and then there are UVA rays, which can affect your retina and your macula. If your retina and macula are damaged enough, macular degeneration and / or permanent blindness can occur.
Solar Eclipse Glasses, however, are made from a material that counteracts all of these types of harmful rays: black polymer, which is “a flexible resin infused with carbon particles,” according to the. OC register. It’s a whopping 100,000 times darker than standard sunglasses (yes, even your high-end and fancy sunglasses), and will block all UV rays, as well as almost all visible light.
According to Pop Sci, legitimate solar eclipse glasses are certified safe according to the ISO 12312-2 standard of the International Organization for Standardization (ISO); if your eclipse glasses have met this safety standard, they will be labeled as such. As NASA explains on its 2017 Total Eclipse website, “If your eyewear or eclipse viewers meet the ISO 12312-2 safety standard, you can watch the un-eclipsed or partially eclipsed Sun through them for as long as you want. Plus, if the filters aren’t scratched, punctured, or torn, you can reuse them indefinitely.
I cannot stress this enough: There are no substitutes for real solar eclipse glasses. You cannot use ordinary sunglasses as solar eclipse glasses. You cannot use 3D cinema glasses as solar eclipse glasses. You cannot use glasses labeled as “solar eclipse glasses” without an ISO 12312-2 label as solar eclipse glasses. You can only use Solar Eclipse Goggles as Solar Eclipse Goggles. Everything else will damage your eyesight.
Remember solar eclipse glasses are 100,000 times darker than sunglasses and block all UV rays and almost all visible light? This is not a joke. As the OC Register explains, sunglasses, which are typically made of glass, plastic, or polycarbonate, block only 10 to 20 percent of daylight and most UV rays; they also allow visible light to pass through. All of this is bad news for your eyes if you look at an eclipse through them; it is just not adequate protection.
What about 3D cinema glasses? They don’t even work the same as solar eclipse goggles. As Mental Floss explains, current 3D film technology is based on linear polarization stereoscopy:
Two images are projected through polarizers of two different orientations, typically 45 and 135 degrees from the horizon. The projected images are then filtered using polarizing films in the lenses of your glasses en route to your eyes. This way, one image is excluded from your left eye while the other image is excluded from your right eye.
The polarized lenses in 3D glasses do absolutely nothing to block the harmful rays of an eclipse; charred eclipse lenses do not contain anything that allows you to see 3D images. These two types of glasses are simply not interchangeable; they are intended for entirely different purposes.
Plus, you’ll want to do more, additional Make sure your solar eclipse glasses are not fakes. As PopSci notes, counterfeit eclipse glasses are all over at present – and if you’ve ordered yours from somewhere other than a supplier on the American Astronomical Society’s List of Reputable Sunscreen and Viewer Suppliers, there’s a good chance they’re bogus. Unfortunately, it may be too late to purchase another pair from a reputable source; according to the AAS, many suppliers are already exhausted.
However, you can still view the eclipse using a pinhole projector. As the American Astronomical Society’s page on pinhole projection notes, “You simply pass sunlight through a small opening (for example, a hole drilled in a plug) and project an image of the Sun on a nearby surface (for example, another map, a wall, or the ground). This means that when you use pinhole projection to visualize an eclipse, you are not will look through the pinhole directly at the eclipse. (This is how you burn your eyes.) Instead, you will see the shadow thrown by the eclipse as it is thrown through the pinhole on the floor, wall or other surface.
Need some more tips on how to safely view a solar eclipse? Here is. As long as you take the right precautions, you’ll be fine. Take advantage of it, it’s a once in a lifetime event!