How to Safely Watch A Solar Eclipse
Approximately 2-5 solar eclipses take place every year across the world, so there’s a good chance you’ll have the opportunity to watch one. An eclipse occurs when one astronomical body (like a planet, moon, or star) passes into the shadow of another object, thereby temporarily obscuring the view.
On Earth, it’s possible to see two types of eclipses – solar and lunar eclipses. Solar eclipses occur when the Moon moves between the Earth and Sun, blocking the Sun’s view. There are four types of solar eclipses: total, partial, annular, and hybrid (a mix of an annular and total eclipse). Conversely, lunar eclipses occur when the Earth comes between the Sun and the Moon, thus preventing the Sun’s rays from reaching the Moon. There are three types of lunar eclipses: total, partial, and penumbral.
An eclipse is a sight you don’t want to miss. But this begs the question of how you can safely watch an eclipse? With the proper safety precautions, it’s completely possible to safely view an eclipse. But what’s important to note is that it’s never safe to look directly at the sun’s rays, even if it’s partially obscured during an eclipse. As NASA explains, it’s imperative to wear eclipse glasses at all times or use an alternate indirect method of viewing while watching a partial or annular eclipse.
Below, we discuss the dangers of looking at an eclipse with a naked eye and review the precautions you can take to safely and comfortably watch the eclipse happening this week and any others that occur in the future.
Dangers of Viewing an Eclipse with a Naked Eye
It can cause serious damage to watch an eclipse without the right safety precautions, whether total or partial. Specifically, it can result in eclipse blindness or retinal burns, Preventing Blindness explains. This is also known as solar retinopathy, which refers to damage to the tissue in the retina.
On normal days, light is scattered once when it travels from the Sun to our eyes on Earth. But during an eclipse, the light reaching Earth is scattered multiple times, making it more damaging. When you look directly at an eclipse (unless it’s the moment during a total eclipse in which the sun is completely blocked), the light can cause damage to the cells in the retina. It may even destroy the cells. Sometimes the damage from solar retinopathy is temporary, but other times it’s permanent. The time it takes to realize you’ve incurred eye damage from an eclipse can vary. In some cases, the damage is apparent in hours, but it can also take days.
As Preventing Blindness notes, experiencing one or more of the following symptoms can indicate eye damage from an eclipse:
- Loss of central vision
- Distorted vision
- Altered color vision
If you experience any of the aforementioned symptoms after viewing an eclipse, it’s recommended that you seek treatment from an eye care professional as soon possible.
How to Safely Watch an Eclipse: Precautions
Watching a solar eclipse requires the proper safety equipment. Only a total solar eclipse is possible to watch without safety equipment. Even then, this is only safe at the moment the sun is completely blocked by the moon. Otherwise, protective gear is still strongly advised. Conversely, it’s not possible to watch a partial or annular eclipse without protection.
Eclipse Glasses
NASA explains that using eclipse glasses or hand-held solar viewers are the only safe way to directly watch an eclipse. Regular sunglasses or homemade filters are not sufficient to adequately filter out the light emitted during a solar eclipse. The American Astronomical Society (AAS) provides a list of certified manufacturers and vendors who make solar filters and viewers. Please ensure that any eclipse glasses you purchase are compliant with existing safety standards and regulations.
Pinhole Projection
This is a common and easy way to indirectly view an eclipse. It’s also one of the least expensive options. Essentially, by creating a pinhole in cardstock and using a separate plain piece of paper held several feet away, it allows you to project the image of the eclipse as it’s happening live. NASA provides step-by-step instructions for how to quickly make a pinhole camera. All that you need is some pieces of card stock or cardboard, aluminum foil, tape, and a pin or paper clip.
Telescope with Solar Filters
One of the best ways to view an eclipse is through a telescope, as it magnifies the image so you can better see the progress. Not only will you need a telescope, but it’s also important to ensure the telescope is fitted with a solar filter. Be careful to never look through the telescope if it lacks a solar filter. Solar filters that attach to the eyepiece are also not sufficient, despite being found in older or cheaper telescope models. Rather, a solar filter is required at the large end of the scope.
T.V. and Social Media
If you can’t or don’t want to secure the proper protective gear required to view an eclipse, there are still options for how you can watch it. Many television stations will broadcast the event live, or at the very least, will give a re-cap of events with footage after it’s concluded. Similarly, many folks will be live streaming the eclipse via social media. Finally, you’ll also be able to find plenty of footage and photos of the eclipse online afterwards, especially on YouTube or news websites.
To learn more about all things vision, including how LASIK eye surgery may provide a long-term solution to your eyesight problems, be sure to visit our blog.