There’s a solar eclipse coming this Monday, and I’ve fielded many questions about how to safely view this highly anticipated event. I should point out that while Colorado Springs won’t be getting the complete eclipse (just a partial), it will still be an event that you won’t want to miss! After all, the last time a total solar eclipse covered the entire width of the U.S. was in 1918, and the next astronomical event like this won’t happen again until 2024!
“Dr. Snyder, can I just wear really dark sunglasses?”
Fiction: Sunglasses will be able to protect me when I look at the sun. It’s even in their name.
Fact: Sunglasses will not help, and they may actually be worse for you than viewing with your naked eye. This is because sunglasses are designed to filter out non-direct ultraviolet light from the sun, but they allow much of the vision light spectrum and infrared (IR) light to pass right through. If you’ve ever seen someone use a high-powered lens to concentrate sunlight and burn an ant or a rock, that’s essentially the same as looking at the sun (with or without sunglasses). Just like those lenses, the human eye has optical components designed specifically to concentrate light into a point focus on the macula, the part of your retina responsible for your sharp, central vision. If you burn your macula (“solar retinopathy/maculopathy”), you could temporarily or permanently lose your central vision…think of the implications that would have on reading or just trying to look at someone’s face!
“Dr. Snyder, what if I look away really quickly or if it ever starts to feel uncomfortable?”
Fiction: As long as you look away when it starts to feel uncomfortable, then you should be just fine.
Fact: The retina does not have pain receptors like the cornea does. When you scratch your cornea (the very front of your eye), it’s REALLY painful but heals pretty quickly. When you burn your retina by looking at the sun, you probably won’t feel a thing, but you could easily lose your central vision forever. It’s just not worth the risk.
“Dr. Snyder, will any solar filters/glasses/viewers that I find online be safe? Some are much cheaper than others…”
Fiction: As long as they say that they’re for viewing the sun, anything online you buy should be safe.
Fact: Things on the internet aren’t always what they seem, and people sell fake products under the guise of false branding ALL THE TIME, not just for eclipse viewing technology. Definitely check out NASA’s site and review their list of reputable vendors. In addition, be sure that whatever you purchase is marked “ISO 12312-2”, which indicates a filter certified to not only reduce visible sunlight to safe and comfortable levels but also block solar UV and IR radiation.. If you don’t have a legitimate solar eclipse viewer, just stick with making a pinhole viewer (you can find instructions on YouTube for making your own); you’ll be viewing the eclipse indirectly, but you’ll be safe!
If you have additional questions, please do not hesitate to consult an optometrist or ophthalmologist. Your local astronomy society is often also a good source of information for safely viewing solar eclipses. So get out there, get educated, be safe, and enjoy the eclipse!