‘Eclipse blindness’ is real and irreversible, ophthalmologist cautions

Dr. Yi Ning J. Strube demonstrates how to use eclipse glasses to protect your vision. Photo submitted.

Total solar eclipse day — April 8, 2024 — is fast approaching, and you have likely been hearing a lot about buying eclipse glasses or picking up free ones distributed by local agencies and organizations. But are they really necessary?

Yes.

Of course, if you intend to stay inside on April 8 and not look up at all, you will be fine without the funny cardboard spectacles. But for those interested in seeing this once-in-a-lifetime phenomenon, Dr. Yi Ning J. Strube has specific advice on how to avoid the severe and irreversible retinal burns caused by looking at the eclipse with the naked eye.

Dr. Strube is the Director of Pediatric Ophthalmology and Adult Strabismus at Queen’s University and Kingston Health Sciences Centre, an Associate Professor in the Department of Ophthalmology, and President of the Canadian Association for Pediatric Ophthalmology and Strabismus.

Strube points out that school boards changed their next professional activity (PA) day to April 8 from its original date, April 12. In her opinion, that was a good move, because the eclipse will happen right at dismissal time when it would be challenging to keep kids from watching the eclipse.

The dimming effect of the moon blocking out the sun during an eclipse gives a false sense of security, says Strube.

“As the sun is being blocked towards totality, it’s actually that period of time just before and after totality which is the most dangerous, because we don’t have that natural avoidance reflex, the squinting reflex of looking at the bright sun,” she explains.

However, despite seeming less bright, the sun’s rays are just as damaging to the eyes during an eclipse as they would be if you were “staring at the full bright sun,” and they can cause burns to the retina, Strube says.

“Eclipse blindness,” also known as solar retinopathy, happens when light destroys the cells in the retina (the back of the eye) that transmit what you see to the brain. This damage, Stube explains, can be temporary or permanent and occurs with no pain. It can take a few hours to a few days after viewing a solar eclipse to realize the damage that has occurred. 

That damage might be indicated by symptoms like blurring, sensitivity to light, or warped vision, called metamorphopsia. Another symptom one might experience is having spots of vision missing; these spots are called scotomas.

“Unfortunately, those scotomas, those blacked out parts of your vision, do not come back. It’s permanent damage, and there’s no treatment… There’s nothing to be done,” Strube says.

The number one thing Strube recommends is protective eyewear that is specifically designed for viewing an eclipse.

“You can’t wear regular sunglasses or prescription glasses, or even [use] your phone; your camera will actually be damaged. Looking directly at the eclipse is just [as dangerous as] looking at the sun on a normal day is dangerous.”

The only time it is safe to take off your eclipse glasses, according to Strube, is when the moon has totally covered the sun. The U.S. government’s National Aeronautics and Space Administration (NASA) indicates that most places along the centerline (path of totality) will see this “totality” duration between 3.5 and 4 minutes.

Strube cautions, “The glasses should be worn at all times. The only time you can take the glasses off — if you’re a responsible adult or an older child who understands what to do — is during that [period of totality]… And then the physicists and the astrophysicists tell us it’s this amazing experience of seeing the corona around the sun.”

A graphic showing the path of totality during the total solar eclipse of April 8, 2024. Graphic via the Ontario Science Centre.

Strube has never experienced this herself and is looking forward to checking it out.

“It sounds pretty great,” she says — with the caveat that it must be timed just right “because if you don’t, just before and after [totality] you’re at risk of the damage.”

Strube says with children staying home from school it is important that they are supervised. Parents can encourage kids to wear the glasses properly by practising beforehand. However, she also knows this may be difficult: “I’m a pediatric ophthalmologist, and I also have three young kids. And you know, kids barely keep their mitts on,” so keeping the glasses on might prove challenging for parents, she says.

It is also important to remember that the eclipse glasses are blackout glasses.

“You cannot move around with them; they are complete pitch dark. So you have to be still. And this goes for adults and kids: if you have them, try them on maybe the day before the eclipse. But then keep them somewhere safe because if [kids are] running around playing with them and they get scratched up, they won’t work. Make sure the glasses are in good shape,” says Strube.

For people who wear glasses, this practice is also important to figure out how to wear the protection over normal glasses.

Dr. Yi Ning J. Strube is the Director of Pediatric Ophthalmology and Adult Strabismus at Queen’s University and Kingston Health Sciences Centre, an Associate Professor in the Departments of Ophthalmology, and President of the Canadian Association for Pediatric Ophthalmology and Strabismus. Photo submitted.

Strube advises that you look down at the ground to put on the glasses before looking up at the eclipse, and to remove the glasses, look down at the ground to avoid looking at the eclipse by accident.

Alternatively, there are many safer ways to experience the solar eclipse, she says.

“I believe NASA, their website is going to be showing it live. There’s ways you can look with a pinhole, and you can go on NASA’s website or our ophthalmology website for links on how to do that,” the ophthalmologist shares.

All in all, Strube is looking forward to the “amazing day of the experience,” but encourages people to plan ahead for vision safety and because of the crowds.

“Our hospitals say the projections will be 70,000 people in town, and apparently the City of Kingston said half a million. You do not want to be driving home from work during that time,” she says, noting that not just because of the temptation to look up.

For more tips on eclipse viewing, Strube recommends checking out the Queen’s University 2024 Eclipse page; it will tell you where you can get free eclipse glasses in Kingston. Lennox and Addington residents can attend Eclipse 101, a Zoom event sponsored by L&A Libraries, to learn more ways to enjoy eclipse day safely and receive a free pair of eclipse glasses. Registration is required.

On April 8, NASA will host live coverage of the eclipse on NASA+, the agency’s website, and the NASA app beginning at 1 p.m. NASA will also stream the broadcast live on its FacebookXYouTube, and Twitch social media accounts, and will also have a telescope-only feed of eclipse views on the NASA TV media channel and YouTube.

For all things 2024 total solar eclipse in Kingston, including viewing events, where to find glasses, things to do before and after the eclipse, and more, visit Kingstonist’s guide to the total solar eclipse 2024.

2 thoughts on “‘Eclipse blindness’ is real and irreversible, ophthalmologist cautions

  • Hello, the PA day is April 8th, I assume moved FROM April 12th.

    • Hi Jessica,
      You are correct, we had inadvertently switched the dates by mistake. The article has now been updated to reflect the correct dates; the PA Day is to take place on April 8, the same day as the eclipse.
      Thanks for bring that to our attention!

      Tori Stafford
      Editor
      Kingstonist

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