The upcoming celestial event is set to captivate millions of viewers across the United States on April 8, 2024, as a solar eclipse takes center stage. While the prospect of witnessing this phenomenon is thrilling, it's crucial to approach it with caution, as observing it incorrectly can pose risks to eye safety.
During a solar eclipse, the moon moves between the sun and Earth, obscuring the sun's rays. A partial solar eclipse occurs when the moon covers a portion of the sun, while a total solar eclipse happens when the moon aligns perfectly with the sun, blocking its entire light source, as NASA clarifies. Regardless of the eclipse's type, protective eyewear is essential for safe viewing.
"The solar eclipse promises to be a breathtaking sight, and I encourage everyone to witness it firsthand — but it's imperative to do so responsibly," emphasized Dr. Jason P. Brinton, an ophthalmologist and the medical director at Brinton Vision in St. Louis.
Guidelines for Safe Viewing
Understanding the potential risks is key to ensuring a safe viewing experience.
Exposure to the sun's ultraviolet rays and infrared radiation, even when partially obscured during an eclipse, can lead to eye damage, cautioned Dr. Yehia Hashad, a retinal specialist, ophthalmologist, and the chief medical officer at eye health company Bausch + Lomb.
"A very small dose could cause harm to some people," he said. "That's why we say the partial eclipse could also be damaging. And that's why we protect our eyes with the partial as well as with the full sun."
Some say that during a total eclipse, it's safe to view the brief period time when the moon completely blocks the sun without eye protection. But experts warn against it.
"Totality of the eclipse lasts only about 1 to 3 minutes based on geographic location, and bright sunlight suddenly can appear as the moon continues to move," notes an eclipse viewing guide published in JAMA, adding, "even a few seconds of viewing the sun during an eclipse" can temporarily or permanently damage your vision.
Do I need special glasses for eclipse viewing?
Yes. Eclipse glasses are needed to protect your eyes if you want to look at the eclipse.
Regular sunglasses aren't protective enough for eclipse viewing — even if you stack more than one.
"There's no amount of sunglasses that people can put on that will make up for the filtering that the ISO standard filters and the eclipse glasses provide," Brinton said.
You also shouldn't look at the eclipse through a camera lens, phone, binoculars or telescope, according to NASA, even while wearing eclipse glasses. The solar rays can burn through the lens and cause serious eye injury.
Eclipse glasses must comply with the ISO 12312-2 international safety standard, according to NASA, and should have an "ISO" label printed on them to show they comply. The American Astronomical Society has a list of approved solar viewers.
Can't find these, or they're sold out near you? You can also make homemade viewers, which allow you to observe the eclipse indirectly — just don't accidentally look at the sun while using one.
How to keep kids safe during the solar eclipse
Since this eclipse is expected to occur around the time of dismissal for many schools across the country, it may be tempting for students to view it without the proper safety precautions while getting to and from their buses. That's why some school districts are canceling classes early so kids can enjoy the event safely with their families.
Dr. Avnish Deobhakta, vitreoretinal surgeon at New York Eye and Ear Infirmary at Mount Sinai, said parents should also be careful because it can be difficult for children to listen or keep solar eclipse glasses on. "You want to actually, in my opinion, kind of avoid them even looking at the eclipse, if possible," he said. "Never look directly at the sun, always wear the right eclipse sunglasses if you are going to look at the sun and make sure that those are coming from a reliable source."
Brinton suggests that to prepare for the eclipse, individuals should start by viewing professional photos and videos of an eclipse online or by visiting a local planetarium.
This way, they can "have an idea of what to expect," he explained.
He also suggests checking out the resources provided by the Prevent Blindness foundation, which offers information on eclipse safety for families.
What happens if you look at a solar eclipse without eclipse glasses?
Even though your eyes may not immediately feel pain when looking at the eclipse without proper eye protection due to the reduced brightness and the location of the damage in the eye, it is important to be cautious as the rays can still cause harm.
The damage may not be noticeable right away and could manifest a few days after the exposure, affecting one or both eyes.
While some individuals may recover their normal vision, there are cases where the damage is permanent.
Brinton stated, "Often there will be some recovery of the vision in the first few months after it, but sometimes there is no recovery and sometimes there's a degree to which it is permanent."
How long do you have to look at the eclipse to damage your eyes?
Experts warn that any duration of looking at the eclipse without proper eye protection is considered too long and can result in eye damage.
"In some cases, a quick glance at the eclipse may not cause damage, but in others, even a fraction of a second can lead to harm," Brinton explained. He shared about patients who have experienced solar retinopathy, the formal term for this condition.
Deobhakta recounted a case where a patient gazed at the 2017 solar eclipse for 20 seconds without proper eye protection. As a result, she now has a permanent crescent-shaped damage that affects her vision.
"The burnt crescent on the retina appears as a black spot in her visual field," he described. "The visual impairment she is facing is irreversible."
Identifying Signs of Eclipse-Related Eye Damage
Indications of eye damage post-eclipse observation include headaches, blurry vision, dark spots, alterations in color perception, and changes in how shapes and lines are perceived.
Regrettably, there is no specific treatment for solar retinopathy.
"It is advisable to consult an eye care specialist for a confirmed diagnosis and guidance," recommended Brinton. However, he noted, "at present, there are no active interventions available. Patients need to be patient and allow time for the body to heal to some extent."
