As Excitement Builds for April’s Total Eclipse, Doctors Warn of Permanently Burnt Retinas
The scene was jarring: etched onto the retina at the back of a 26-year-old woman’s eye was the haunting shape of a crescent solar eclipse. In scans performed by doctors at New York’s Mount Sinai infirmary in 2017, the distinctive contours of the moon’s silhouette obstructing the sun were burned into her vision in disturbing detail.
The Staten Island woman’s case, documented in the medical journal JAMA Ophthalmology, was a visceral reminder of the serious risks of carelessly watching solar eclipses with unprotected eyes. While rare, such permanent retinal burns from exposure to the sun’s concentrated rays have been a recurring hazard during eclipses throughout history.
“It’s essentially a laser pointer being pinpointed into the eye from the exposed portion of the sun itself,” said Dr. Avnish Deobhakta, the Mount Sinai ophthalmologist who treated the woman. “It can absolutely destroy parts of the retina in the telltale shape of the eclipse.”
As fervor mounts ahead of April 8th’s total solar eclipse stretching from Mexico across a huge swath of the United States, eye experts are issuing urgent warnings to the millions expected to witness the celestial phenomenon. Looking up at the partially eclipsed sun without approved protective eyewear can permanently scorch vision in a matter of seconds.
“The human eye is simply not designed to safely look directly at the sun’s rays when any portion of the sun’s disk is exposed,” said Dr. Ron Benner, president of the American Optometric Association. “Just because the sun appears less bright during an eclipse doesn’t make it safer to stare at – it’s actually more deceptively hazardous.”
The Treacherous Allure of Eclipses
During a total solar eclipse when the moon fully obscures the sun’s blazing surface for up to around 2 minutes and 40 seconds along a narrow path, it is safe to view the event with the naked eye. In fact, turning away from the sun during the brief period of totality would defeat the whole purpose for many avid eclipse chasers.
The grave dangers arise before and after totality when even a sliver of the sun’s disk remains uncovered by the moon. The natural instinct to squint or look away from direct sunlight is suppressed, allowing harmful radiation to flood the light-detecting retinal tissue for longer stretches of time.
“People think if the sun isn’t as bright as usual, it’s not as dangerous, but that couldn’t be farther from the truth,” said Deobhakta. “Outside that narrow window of totality, the concentrated rays act like a laser burning through the retina instead of just generalized brightness.”
The hazardous effects were seared into the vision of childhood friends Lou Tomososki and Roger Duvall over 60 years ago as teenagers in Oregon. During a partial solar eclipse in the early 1960s, the pair stared at the sun without protection for around 20 seconds from their high school’s baseball diamond after being warned about potential eye damage. Ever since, both men have had permanent blind spots obstructing portions of their visual fields.
“Most of the time I don’t think about it, but when I close an eye it’s definitely noticeable,” said the 77-year-old Tomososki, a retired truck driver. “I’ll be looking at something yellow like a daffodil flower, but that spot just blocks out a circle of the color right in the middle.”
Echoing the recommendations of doctors, the longtime friends have made it a mission to caution younger generations about the importance of proper eye protection during eclipses.
“I got kind of a personal involvement with Mr. Sun that day that’s still affecting me over half a century later,” Tomososki said. “It’s not something to take lightly.”
How to View Eclipses Safely
Fortunately, preventing retinal damage during a solar eclipse is straightforward by following simple precautions. For observers outside the path of totality who can only see a partial eclipse, the universal advice is to never look directly at the sun without certified eclipse glasses or viewers.
Approved by the American Astronomical Society (AAS), these special specs are designed to block nearly all light from the sun except for a small portion of the outer red portion of the visible spectrum. Welding goggles or regular sunglasses offer nowhere near enough protection against the retina-scorching radiation.
“There’s no replacement for getting legitimate eclipse glasses or viewers that meet the ISO safety standards,” said Rick Fienberg, who leads the AAS’s solar eclipse task force and has witnessed 14 eclipses. “Stay away from random knockoffs or homemade filters – it’s just not worth the permanent risk to your eyes.”
For those without access to proper filters, the safest approach is turning away from the sun entirely. Pinhole projectors constructed by overlapping fingers to form a small opening can indirectly cast the sun’s image onto a flat surface for viewing. The same effect can be achieved by letting sunlight pass through a colander or index card with a hole punched in it.
“While it lacks the drama of seeing the eclipse directly, these indirect techniques are by far the safest way to appreciate the event,” said Fienberg. “Unless you’re inside the path of totality for the couple of minutes it’s completely safe to look, just appreciate it in other ways.”
Incredibly Rare But Very Real Damage
The eclipsed portion of the sun may appear benign to our eyes, but make no mistake: looking at it is tremendously hazardous. Doing so focuses an immense amount of radiation into a tiny area on the retina, burning the light-sensing rod and cone cells.
“It’s not at all like getting a sunburn on your skin, which is just short-term reddening and irritation,” explained Benner. “This permanently destroys the precious retinal tissue integral to processing visual images and information sent to the brain.”
While retinal burns are extremely uncommon compared to the huge numbers of people who safely watch eclipses, the potential consequences are sobering. In addition to the woman in Staten Island, other cases from the 2017 eclipse were reported in medical literature.
In one instance documented in JAMA Opthalmology, a young man in Arizona gained a crescent-shaped blind spot in his field of vision after looking directly at the sun for around 15 seconds with a camera viewfinder. The precise curved outline of the invisible burn mirrored how much of the sun’s surface was exposed at that moment.
“We can see damage down to the cellular level on some of these scans,” said Deobhakta. “People may sustain blind spots or distortions making straight lines look bent, but there could also be much more widespread losses we can’t fully visualize.”
Considering the rarity versus the millions who viewed the 2017 Great American Eclipse, fewer than 100 reported cases of eye injuries sounds like an insignificant number. But any permanent disability is one too many for an event that is utterly preventable with simple precautions.
Opportunity of the Decade for Eclipse Viewers
For many professional astronomers and amateur stargazing enthusiasts alike, the arrival of a solar eclipse sparks levels of joy and anticipation rivaled by few other experiences. On April 8th, 2024, that electrifying excitement will reach a fever pitch across North America.
Beginning at around 8:30 am Central Time over the Pacific Ocean, the moon’s conical shadow will first make landfall in Mexico before rapidly racing northeast at over 1,500 mph across major U.S. cities like Dallas, Indianapolis, Cleveland, and Montreal. Anyone situated within the 115-mile wide path of totality stretching from Texas to Maine will be treated to a mind-blowing up to 4 minutes and 28 seconds of true high noon darkness.
“A total eclipse of the sun is simply one of the most awe-inspiring sights in all of nature,” said veteran eclipse chaser Fienberg, who plans to bask in the cosmic spectacle from a Mexican resort. “All of the normal rules about never looking at the sun are suspended during those fleeting moments of totality when the sun’s blazing outer atmosphere is put on display.”
Fienberg is among the veteran group of astronomy diehards who have turned chasing eclipses into an obsessive lifestyle pursuit spanning decades and globetrotting to dozens of countries. However, most everyday folks may only be treated to this breathtaking sight a handful of times throughout their entire lives.
“For many locations across the U.S., this could represent the best opportunity in our lifetimes to experience a total solar eclipse,” said Benner. “Of course, the built-in ‘total’ part makes it safe to soak in with the naked eye, unlike most of the times when we only see it partially eclipsed.”
With a continent’s worth of eyeballs turned towards the heavens in rapturous awe on April 8th, eclipse mania is bound to reach feverish levels over the coming weeks. Eye care professionals are hoping their preventative messaging hits home to avoid more painful stories of permanent vision loss.
“Even if you’ve never been an eclipse chaser before, this is going to be the epiphany that spawns newfound fascination for many Americans,” said Fienberg. “But by respecting the sun’s power and knowing how to watch safely, it can be a stunning lifetime memory instead of a scarring one.”
