In 1962, a teenager in Oregon named Lou Tomososki and a friend both made the mistake of looking directly at a partial solar eclipse without any protective eyewear. Tomososki saw bursts of light, like those from a flashbulb. His vision in his right eye never recovered. “You know how the news people blur a license plate out,” he recently told NBC News. “That’s what I have on the right eye, about the size of a pea. I can’t see around that.”
A complete solar eclipse is said to be so awe-inspiring that people who experience one become addicts. On Monday (Aug. 21), a wide swath of the US will get to view such an event.
For those in the path of “totality,” when the moon completely blocks the sun’s face and reveals its corona, it will be safe for a few minutes to look directly at the eclipse with your naked eyes, according to NASA. But most of the US isn’t in that path. For all those people, to look even for a moment without certified protective eyewear can cause permanent damage.
In an Aug. 18 article for JAMA Ophthalmology, two eye experts explained what actually happens to your eye if you look at an eclipse. There are two types of damage sunlight can inflict. One is “direct thermal injury,” caused by near-infrared radiation, meaning the light can literally burn your eye. Because you can’t see that type of light, and because your retina—the light-sensitive tissue lining inside your eye—doesn’t have pain receptors, the damage can occur without you even knowing it.
But the more concerning sort of damage is called photochemical toxicity, and it results from the light you can see. As that light passes through the eye, the normal chemical processes within the eye generate free radicals and what are called reactive oxygen species. In excess, as happens when your eye gets hit with a direct shot of sunlight, those atoms can destroy your retinal tissue. The article’s authors cite a 1999 study of eclipse burns from the UK that photochemical toxicity was the more frequent cause of sun-induced retina damage, known as “solar retinopathy.”
As it happens, young adults—perhaps especially young males—are those most likely to suffer these eye injuries from the eclipse. “Although a clearer lens [in the eye] that is more permissive to transmitting visible light may contribute to this finding, a more likely explanation may be simple misunderstanding of the danger of viewing an eclipse without proper protection or misuse of that protection,” the authors write.
Those who want to watch the 2017 eclipse, or photograph it, need to make sure they take the proper precautions. Looking through a telescope, binoculars, or a camera lens without the right eyewear isn’t safe either. The event will only last a few minutes, but the damage it can cause could last a lifetime.
Since it’s never safe to look at the partially eclipsed or uneclipsed Sun, everyone who plans to watch the eclipse needs a plan to watch it safely. One of the easiest ways to watch an eclipse is solar viewing glasses – but there are a few things to check to make sure your glasses are safe:
- Glasses should have an ISO 12312-2 certification
- They should also have the manufacturer’s name and address, and you can check if the manufacturer has been verified by the American Astronomical Society
- Make sure they have no scratches or damage
To use solar viewing glasses, make sure you put them on before looking up at the Sun, and look away before you remove them. Proper solar viewing glasses are extremely dark, and the landscape around you will be totally black when you put them on – all you should see is the Sun (and maybe some types of extremely bright lights if you have them nearby).
Never use solar viewing glasses while looking through a telescope, binoculars, camera viewfinder, or any other optical device. The concentrated solar rays will damage the filter and enter your eyes, causing serious injury. But you can use solar viewing glasses on top of your regular eyeglasses, if you use them!
If you don’t have solar viewing glasses, there are still ways to watch, like making your own pinhole projector. You can make a handheld box projector with just a few simple supplies – or simply hold any object with a small hole (like a piece of cardstock with a pinhole, or even a colander) above a piece of paper on the ground to project tiny images of the Sun.
Of course, you can also watch the entire eclipse online with Nasa. Tune into nasa.gov/eclipselive starting at noon ET on Aug. 21!
For people in the path of totality, there will be a few brief moments when it is safe to look directly at the eclipse. Only once the Moon has completely covered the Sun and there is no light shining through is it safe to look at the eclipse. Make sure you put your eclipse glasses back on or return to indirect viewing before the first flash of sunlight appears around the Moon’s edge.
You can look up the length of the total eclipse in your area to help you set a time for the appropriate length of time. Remember – this only applies to people within the path of totality.
Everyone else will need to use eclipse glasses or indirect viewing throughout the entire eclipse!
Photographing the Eclipse
Whether you’re an amateur photographer or a selfie master, try out these tips for photographing the eclipse.
#1 — Safety first: Make sure you have the required solar filter to protect your camera.
#2 — Any camera is a good camera, whether it’s a high-end DSLR or a camera phone – a good eye and vision for the image you want to create is most important.
#3 — Look up, down, and all around. As the Moon slips in front of the Sun, the landscape will be bathed in long shadows, creating eerie lighting across the landscape. Light filtering through the overlapping leaves of trees, which creates natural pinholes, will also project mini eclipse replicas on the ground. Everywhere you can point your camera can yield exceptional imagery, so be sure to compose some wide-angle photos that can capture your eclipse experience.
#4 — Practice: Be sure you know the capabilities of your camera before Eclipse Day. Most cameras, and even many camera phones, have adjustable exposures, which can help you darken or lighten your image during the tricky eclipse lighting. Make sure you know how to manually focus the camera for crisp shots.