You’ve been told direct viewing of an eclipse is dangerous, so does a solar eclipse damage your eyes? While the event is fascinating and certainly a rare opportunity, it’s also something which needs to be seen safely. Naturally, you don’t stare at the sun, so it’s the same rule for a solar eclipse. (Looking for a complete guide to solar eclipses?)
But why is that? After all, the moon is obscuring the sun. During totality, the sky darkens enough it appears as nighttime, so wouldn’t that be safe to view? Still, the answer is no, and we’ll explain why.
First, understand a solar eclipse is only safely observable through project sheets, boxes, special lenses, welder shades, or video streams. Regular sunglasses don’t work, and neither do cameras on smartphones or other devices. Trying to view an eclipse this way will still cause eye damage.
So why does the solar eclipse cause eye damage? Well, naturally, you don’t stare at the sun for prolonged periods (or at all). However, even if a few seconds of direct exposure to the sun isn’t usually enough to cause permanent problems. What makes the eclipse different?
Primarily, during totality, the sun is obscured by the moon – this you know. During this time the only visible part of the sun is the “corona,” or a rim of glowing light. However, as the moon transitions from totality to partial, light shines through in an extremely focused manner. Viewing this transitional light causes extreme damage to the eyes by burning the cells in the retina, causing loss of sight and blindness.
Can an eclipse blind you? Yes. This is known as retinopathy. Eyes are overwhelmed with sunlight when this occurs. The worst part is, this generally has no sensation or pain, so a person won’t know their eyes are damaged. Imagine looking at an eclipse transition for longer than ten seconds – only to stop once you realize blindness has occurred. Even then, this may only happen afterward rather than immediate – essentially it’s like getting a cut but not feeling the pain, making the injury worse. (Note that solar and lunar eclipses are different, and must be observed differently.)
This danger is increased because of the darkness. Pupils will not contract and respond normally since there’s an absence of light, so the abrupt brightening during a partial transition means more sunlight is absorbed into the retina. Of course, this isn’t a good thing. Once eye damage occurs, all sorts of potential symptoms result from it.
Even historical astronomers had issues with eye damage. Isaac Newton, for instance, suffered blindness for three days after observing light for too long, and would experience afterimages months after. They didn’t realize how dangerous eye damage was until after the fact, which is why it’s important to view these events safely.
Light damage is, fortunately, treatable on its own, and generally symptoms can disappear after a few days. In other cases, said symptoms can persist for up to a year. It’s only after extreme exposure has occurred that long term, immediate damage is suspected.
To help you understand them, we’ll go over a few symptoms.
Solar Eclipse Eye Damage Symptoms
If you believe you’ve damaged your eyes (or someone you know) it’s important to recognize the symptoms and seek treatment as soon as possible. It’s not always apparent damage has occurred since symptoms can appear hours after viewing an eclipse, even days. Here, however, are general issues to look for:
- Blurring vision, sometimes seeing after images (more than one object appearing)
- Central blindness in one or both eyes
- Vision distortion and/or impairment
- Light sensitivity, such as soreness in regular room light
- Alterations in how one perceives color (not color blindness) – referred to as chromatopsia
Any of these indicate harm towards the eye, and medical attention is needed by an eye specialist. If addressed in a timely fashion, damage can be reversed, but otherwise permanent if left alone too long. If you experience any of the problems listed, schedule an appointment with an eye doctor (Ophthalmologists) as soon as possible.
The good news is, these symptoms are reversible when treated properly (assuming no severe damage has occurred). When visiting a specialist, they’ll first examine your eye to assess the level of damage caused and then provide a treatment path afterward. This could be anything from resting the eyes and protecting them from additional light exposure to procedures for the retina.
How can I protect my eyes?
Obviously, avoid looking directly at a solar eclipse. As for watching the event safely, be sure to wear or use proper equipment. This typically includes:
- Special welder shades or solar eclipse glasses.(Solar eclipse glasses can even be made at home. Click here to see how to make DIY solar eclipse glasses!)
- Proper lenses with solar filters for photographic equipment/devices.
- Projector boards/projector sheets.
- A DIY solar eclipse viewing box.
Also, take special care with infants and pets. They’re just as susceptible to eye damage if not protected.
Be wary of protective gear that claims to be safe for use when it may not be. NASA recommended shader values of 12 and above (the type of material capable of protecting against sunlight) for sunwear. Anything less is not sufficient. Some vendors try to take advantage of the excitement for a solar eclipse and sell shades which are the improper type.
It’s also a good idea to test any of the above methods before actually viewing an eclipse. Make sure a projector sheet will work, make sure lenses are sufficiently protective, and check the specifications on your lenses.
Doing so ensures you can view an eclipse event without issue, and also prevents any unexpected surprises.
When exploring how a solar eclipse damages your eyes, you now understand that the sudden influx of light causes serious harm to the cells in the retina, impacting the ability for your eyes to receive information. Even if you don’t feel or experience immediate symptoms, such an experience is dangerous.
Always view the solar eclipse safely. If you experience any of the symptoms we described, see a specialist as soon as you can. (Looking for even more information about solar eclipses? Check out our guide to our favorite solar eclipse telescopes here!)