A solar eclipse is one of the most incredible things you can witness on Earth. The sky dims, leaves miniature crescents all over the ground, and if it’s a total eclipse, you’ll see rippling shadows racing on the ground. Sadly, eclipses are also dangerous for your vision. Here’s how to stay safe.
How to Safely View a Solar Eclipse
In order to safely view any eclipse, you must wear special protective glasses, usually called “solar viewers” or “solar eclipse glasses.” Eclispe glasses function like sunglasses, but the amount of light they block is much higher (thousands of times as much), and they usually look quite different.
The American Astronomical Society maintains a list of manufacturers known to produce safe solar viewers, and you should always buy from one of them. Be very careful purchasing them online—counterfeits that do not meet the appropriate safety standards show up on Amazon and other storefronts every time there is an eclipse.
You cannot, under any circumstances, use regular sunglasses to attempt to view an eclipse. You will damage your eyesight.
When you get your eclipse glasses, carefully inspect the lenses to make sure they’re not damaged in any way. Scratches or tears can make them less effective.
Can You Ever Look at an Eclipse Without Solar Eclipse Glasses?
There is one instance where you can view an eclipse with the naked eye: during the totality of a total solar eclipse (not an annular solar eclipse). During totality, the entire surface of the Sun is obstructed by the Moon. The only thing you can see is the corona—the outer atmosphere of the Sun. It is important that you time this precisely. Even a small sliver of the Sun is capable of delivering a harmful amount of light to your eyes. There are a few ways you can know if you don’t have the exact time on your watch or phone.
If you’ve ever viewed a partial solar eclipse while standing under a leafy tree, you probably noticed that the light passing through the leaves was projected as little crescents, exactly mirroring the shape of the eclipse. In this case, the leaves have naturally created a pinhole projector. All partial eclipses produce this effect, but a solar eclipse at totality doesn’t. The crescents will vanish once the Sun reaches totality. You can poke small holes in a piece of paper to replicate this if you want, but your average kitchen colander will work too.
Additionally, you’ll sometimes see rippling shadows called shadow bands moving across the ground as the eclipse reaches totality; it looks almost like rippling water. There is a bit of uncertainty about why this happens, but scientists know that it is related to how the narrow shaft of light from the Sun is distorted by the turbulence in the atmosphere. Shadow bands only appear very briefly before and after totality, so if you’re seeing them, and then they suddenly disappear, you know you’re at totality.
Shadow bands can be tough to spot on surfaces with a lot of variation in color and texture. They’re pretty easy to see on a plain piece of paper, though.
How and Why Do Solar Eclipses Occur?
Protect your eyes—wear eclipse glasses for a cosmic event view!
You Can Safely Photograph the Eclipse With the Right Equipment
Your camera (be it a DSLR or your phone) is also vulnerable to the Sun during a partial eclipse. Just like your eyes, your camera needs special protection if you intend to point it directly at the Sun.
The big thing to keep in mind here is proper fitting. It is difficult to hold eclipse glasses in front of your phone’s lens, and no glasses are large enough to cover the lens of a full-sized camera. If you’re going to attempt it, you need to buy the appropriate filter for your camera or for your phone.
If you don’t, you could irreparably damage your phone, and you will damage a camera.
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Taking Photos of the Eclipse Can Ruin Your Phone (Here’s How to Avoid That)
Don’t attach it to a telescope either.
What About a Telescope?
Under no circumstances should you ever look through a regular, unfiltered telescope at the Sun at any time. What little margin for safety exists with looking at the Sun without solar glasses on vanishes when you’re looking through a telescope. You will irreparably damage your vision; you could even lose your eye. Don’t do it.
There are special solar telescopes that come equipped with filters that make it safe to view the Sun. They tend to be smaller than most telescopes since you don’t really need extraordinary magnification or light-gathering ability to examine the Sun—it is massive and extremely bright.
Celestron EclipSmart Safe Solar Eclipse Telescope
$94.95 $166.9 Save
$71.95
The Powerseeker 60AZ is an inexpensive starter telescope that comes with a basic solar filter, allowing you view the Sun (including eclipses) without damaging your vision.
- Magnification
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142x (Max)
- Aperture
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2.36 Inches
- Focal length
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28 Inches
There are also filters you can get that attach to regular telescopes, too. Most major telescope manufacturers offer these for their scopes.
If they don’t, you can make one yourself, but it isn’t something you should attempt unless you’re an expert, or can do it with the assistance of an expert.
What Happens If You Look Directly At a Solar Eclipse?
How much damage you do depends on how long you look, whether you’re using magnification, and where the Moon is.
As you might expect, the longer you look at the Sun at any time, the greater your risk is. You can damage the cells that make up your retina, causing blind spots, blurriness, loss of color definition, and plenty of other nasty side effects. You could also damage the exterior of your eye—basically, your eye gets a sunburn. Exposure to the same ultraviolet (UV) light that causes sunburns has been shown in scientific studies to increase your risk of cataracts and other eye diseases.
Magnification of any kind, be it through a telescope, binoculars, or a camera, will dramatically increase your chance of eye injury. You should always avoid it unless you are using the appropriate filtering equipment.
Don’t Assume a Partial Eclipse Makes Looking at the Sun Safer
You shouldn’t assume that looking at a partial solar eclipse is safer than looking at the Sun normally, either. Typically, when you view something that is too bright, your pupils contract and you reflexively squint in order to limit the amount of light that reaches your retina. If you’ve ever had a flash go off in your face, had a friend shine a flashlight at you in a dark room, or stepped outside on a particularly sunny day, you know what this feels like.
But there’s a catch here: your pupil only responds to visible light, not (UV) light. That means you might actually be able to look a partial eclipse without causing your pupils to contract as much, squinting, or averting your gaze to avoid the discomfort. Unluckily, there is still enough UV light reaching Earth during a partial eclipse to damage your eyes.
In some ways, this combination actually makes a partial solar eclipse more dangerous than the Sun normally is. With your regular defensive reflexes down, you might unwittingly expose your eyes to enough UV light to do damage.
There is no guarantee that any damage you do to your eyesight can be corrected by a doctor. Always take the appropriate precautions to protect your vision.
