How to watch an eclipse safely
On August 21, 2017, the entire United states will experience a partial eclipse – and for those lucky enough to be in parts of 11 states, a full eclipse.
The Great American Eclipse of 2017, as it is referred to, offers an exciting opportunity to experience this exciting event.
However, looking directly at the sun an eclipse can permanently damage your vision and potentially blind you, so it is important to plan so you can experience it safely.
Most importantly, the only safe time to look directly at the sun is when it is completely covered by the moon during the totality phase of an eclipse (when it is completely blocked). Areas outside the path of totality will have a partial eclipse, where only part of the sun is blocked – even at the peak of the eclipse.
In any other time, you must protect your eyes or you could damage your retina, which could cause blindness. During the 2017 eclipse, however, the path of totality will only be about 70 miles wide and will move very quickly (you can see the path and find out more at www.eclipse2017.org), so it is best to protect your eyes for the entire eclipse.
How to Protect Your Vision During the Eclipse
Before the eclipse, you want to be prepared for how to protect your eyes. The following steps are from the American Academy of Ophthalmology and the American Astronomical Society:
- Ordinary sunglasses, even very dark ones, or homemade solar filters are not safe for looking at the sun.
- The only way to look at the sun, at any time, is through special-purpose solar filters. These solar filters are used in “eclipse glasses” or hand-held solar viewers, and meet a specific worldwide standard known as ISO 12312-2.
- Inspect your solar filter or eclipse glasses for scratches or damage before using them. If yo use any damage, do not use them.
- Always read and follow all directions that come with the solar filter or eclipse glasses, and help children use handheld solar viewers and eclipse glasses correctly.
- Cover your eyes with your eclipse glasses or solar viewer before you look at the sun, and while looking away.
- Only remove your filter after you turn away from the sun – never remove them while looking at the sun.
- Never look at the uneclipsed or partially eclipsed sun through an unfiltered camera, telescope, binoculars or other similar devices – even if you are wearing eclipse glasses or holding a solar viewer at the same time. The intense solar rays coming through these devices will damage the solar filter and, more importantly, your eyes.
A Safe Alternative: Watch the Eclipse Indirectly
Another great way to see the eclipse is through a pinhole projection or video display.
A pinhole viewer allows you to project an image of the sun onto another surface, like a piece of paper, a wall or the pavement. Plenty of resources are available online to learn how to make your own pinhole device with a few simple supplies.
Consider watching the eclipse online, or through a nearby event where you can trust proper safety measures have been taken.
NASA will also stream the eclipse live on their website, if you prefer to watch form the safety of your computer or mobile device.