What Happens If You Look Directly At a Solar Eclipse? An Ophthalmologist Reveals the Damage
Spoiler alert: Don't.
It’s not an urban legend; looking directly at the Sun, even for a second or two, can burn your eyes — on the inside. The scary part is that you won’t feel it happening, so you’ll only know you’ve permanently damaged your vision once it’s too late.
Don’t believe us? Inverse talked with an ophthalmologist about the gory details, how to avoid burns on the back of your eyeballs, and the prognosis for those who mess around and find out.
What Happens When You Look Directly at the Sun?
It only takes a second for the precisely focused, intense light of the Sun to scorch the ever-living heck out of your retinas, a condition called solar retinopathy. It’s the same type of injury that can happen if you look directly into a laser pointer or at a welder, which are two other things you also should not look directly at.
“The sun is incredibly powerful. It can cause permanent damage to the eye if proper eye protection is not used,” ophthalmologist Purnima Patel, a clinical spokesperson for the American Academy of Ophthalmology, tells Inverse. “The damage can happen in a matter of seconds.”
Most of the work of seeing — turning light into images — happens at the back of the eyeball in a structure called the retina. Cells in the retina called rods and cones translate photons of light into chemical and electrical signals, which travel along nerves to the brain. The brain turns those signals into images.
“When looking directly at the sun, the sun’s powerful rays travel through the eye to the retina. The intense exposure triggers a series of complex chemical reactions in the eye that damage the light-sensitive rod and cone cells that help see,” Patel says.
Some of those chemical reactions happen because the sun’s ultraviolet light produces what chemists call “reactive oxygen species” — molecules with an extra oxygen atom, which react way too enthusiastically with other molecules. These reactive oxygen species are bad news for a lot of the building blocks of life, and you don’t want them in your eyes.
“Protecting your eyes from the Sun, even during a regular non-eclipse day, is one of the best things to do for eyes,” says Patel.
How Do You Know If You’ve Burned Your Retinas?
Retinas don’t have the right nerves to feel pain, so a retinal burn won’t hurt. The first sign that something is wrong will come a few hours later (or maybe even the next day).
For many people, blurry vision is the first sign of a problem, but many also notice a blind spot in the center of their vision; this may show up in one eye or in both (your faithful correspondent, who has a different kind of retinal damage, spent several days trying to clean a smudge off their glasses before realizing the problem was internal).
Other people notice that they’re more sensitive to light than usual, that they see color differently, or that their vision is warped: straight lines may look wavy or curved, or some objects may look smaller than normal. That wonky vision may also cause a headache, usually in the front and sides of the head.
Under an ophthalmoscope, the instrument an ophthalmologist or retinologist uses to see the interior of the eye, a retinal burn may look like a yellow or white spot in the center of the retina, fading to red over the next several days.
So You Messed Around With the Sun – Now What?
There’s no treatment for solar retinopathy, which is why it’s so crucial to avoid it in the first place. The good news is that your eyes may heal on their own.
“We do know that many people recover after three to six months, but some will suffer from permanent vision loss, in the form of a small blind spot and/or distortion,” says Patel. “It’s difficult to provide an ‘average’ prognosis; results will vary from patient to patient.”
Despite the lack of treatment options, Patel says it’s still important to see an ophthalmologist anytime you notice changes in your vision. They can examine your eyes to see the extent of the damage and make sure you actually have a retinal burn and not another condition that can affect your retina (many of which can be treated).
Seriously, Don’t Look Directly at the Sun
Fortunately, avoiding solar retinopathy is extremely simple: don’t look directly at the Sun, a laser pointer, or a welder without proper eye protection. Not even for a second or two. Just don’t do it. Not even if you’re the president. You will have regrets.
It’s so simple that we wonder why people still seem to have trouble with it.
“Perhaps people are still unaware that such a short amount of time can cause such lasting damage to their vision,” says Patel. “People may also assume that because they aren’t experiencing pain—the retina does not have any pain nerves—no damage has been done.”
The safest way to watch the upcoming solar eclipse is through a set of eclipse glasses that meet the ISO 12312-2:2015 standard (look for the label on the packaging or check out the Planetary Society’s advice). There is no number of sunglasses you can stack together to watch the eclipse safely; you need actual eclipse glasses. If you don’t have a set of eclipse glasses on the big day, you can make a pinhole projector or watch shadows on the ground.
Even when the Sun is mostly blocked by the Moon, don’t look directly at it. According to the National Park Service, you can get away with an unprotected view during the two to four minutes of totality (when the Sun’s disk is fully covered), but make sure your timing is exactly right. There is no other safe time to look at the Sun without eclipse glasses. (Your electronics will need their own filters.)