Science Life

How to safely watch the solar eclipse

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All across the country, skygazers are getting ready for the Aug. 21 total solar eclipse – the first total eclipse in the U.S. in decades.

In far-southern Illinois, people will be within the “path of totality,” where they’ll be able to see the full eclipse. In the Chicago-area, residents will be able to view a partial eclipse when the moon blocks about 90 percent of the sun.

It’s important to take steps to protect your eyes, regardless of your location when viewing the eclipse. Staring at the sun – even during a sky-darkening eclipse – requires safety precautions above and beyond wearing dark sunglasses. People who try to watch the eclipse without the specifically designed eye protection risk causing permanent damage known as solar retinopathy and eclipse retinopathy. Even more concerning? People who’ve injured their eyes during an eclipse may not even be immediately aware they’re damaged.

We asked Asim Farooq, MD, an assistant professor of Ophthalmology and Visual Science at UChicago Medicine, to share his best tips to safely watch the eclipse. The expert on corneas and eye disease, who treats patients in Hyde Park and at UChicago Medicine’s new downtown ophthalmology clinic, said he’s been fielding questions from patients for weeks ahead of the big celestial event.

Dr. Asim Farooq

UChicagoMed: What eye damage can happen if you stare at the sun without proper eye protection?

Asim Farooq: The main problem that can occur is damage to the retina, causing loss of vision or even blindness. What is the retina? If you think of the eye as an old-fashioned camera, the retina is like the film. The vision can take several months to recover, or vision loss can even be permanent. There are various names for this condition, such as solar retinopathy and eclipse retinopathy.

How likely is it that you could stare at the sun long enough to actually cause damage? Wouldn’t most people’s eyes reflexively close because of the brightness?

Damage can occur in as little as one minute, and it doesn’t have to be continuous – in other words, staring at the sun for a few seconds at a time still isn’t safe. Because the sky is relatively dark during an eclipse, we may not close our eyes reflexively.

What does the damage feel like? How long does it last?

One of the dangers of eclipse viewing is that we don’t feel any pain while the retina is being damaged. The retinal changes can take several months to recover, or they can be permanent.

What eyewear should you use for a solar eclipse? Can I use sunglasses?

The proper eye protection is thousands of times darker than regular sunglasses and will have a label that says “ISO 12312-2.” Dark sunglasses don’t block enough light to prevent damage to your eyes.

How do special solar filters protect the eye from damage when watching an eclipse?

Special solar filters block not only the intense visible light from the sun, but also other types of light (i.e. ultraviolet and infrared) that can cause damage.

Where should people get eyewear for the solar eclipse? Is there any way to make sure that the eye gear will actually do what it says? Are there any tips people should know when buying the special gear?

Unfortunately, there are some products being sold online with an ISO label that are not up to standard. The American Astronomical Society (AAS) has a list of reputable vendors listed on their website, which I have provided here. I would recommend using one of these vendors.

Have any patients or even friends and family asked you about eye safety tips for the eclipse yet? What’s your best advice? Do you have any other eclipse-viewing tips?

Yes, I’ve had a number of people ask me for safety tips. My best advice is to buy ISO-certified eye protection from a reputable vendor, gather some friends and family, and enjoy the event!

What’s your plan for watching the eclipse?

I plan to spend the day doing eye surgery at the University of Chicago Medicine!

Want more information? Check out the American Academy of Ophthalmology’s solar eclipse eye safety infographic.