Omni Vision and Learning Center
542 Cedar St, Monticello MN 55362
Phone: 763-314-0664
Fax: 763.314.0665
Aug 8

Solar Eclipse 2017

solar eclipse 2017

On Monday, August 21, 2017, a solar eclipse will be viewable to everyone in North America (weather permitting). This will likely be one of the few times you might hear your optometrist encourage you to look at the sun – though only with precaution!

On this day, people across the continent will be able to see a partial solar eclipse that will last between 2 and 3 hours. This eclipse is noteworthy because it will be visible for many Americans from their backyards. Some will even experience the rare and beautiful phenomenon of a total eclipse – though briefly. People within a 70-mile-wide swath from Oregon to South Carolina will, halfway through the eclipse, see the moon completely blocking the sun. During this time, bright stars and even planets will be available for those in the total eclipse area.

Solar eclipses occur when a part or all of the sun is blocked by the moon; more specifically, it’s the occurrence of the moon and the sun being the same “angular size.” The sun is 400 times wider than the moon, and it is also 400 times farther away from earth than the moon. The phenomenon of a solar eclipse happens when they coincidentally appear as the same size in our sky; this is what is meant by them having the same angular size.

The Rarity of a Total Eclipse

Total eclipses are relatively rare on earth; one occurs about every year or every other year. The tricky part is that in order to see a total eclipse, you need to be in the narrow strip of land called the “path of totality” to view the total phase of the eclipse. Generally, this area is pretty far off the beaten path (like across an ocean or the Sahara desert), so very few people in the world have ever seen a total eclipse.

The last time a total solar eclipse was able to be seen in the contiguous United States was February 26, 1979. The path of this total eclipse passed through Oregon, Washington, Idaho, Montana, North Dakota, and the Canadian provinces of Saskatchewan, Manitoba, Ontario, and Quebec. After the August 2017 total eclipse, the next total solar eclipse will occur on April 8, 2024, and will be visible from the United States in a band from Texas to Maine.

Total eclipses are almost as short as they are rare: once a total eclipse begins, there is only a minute or two of totality before the sun starts to become visible again.

Tips for Viewing the Eclipse Safely

pinhole camera solar eclipse

See this pinhole camera guide from NASA’s Jet Propulsion Laboratory at the California Institute of Technology.

Because a solar eclipse of any kind would have you looking in the direction of the sun, it’s extremely important to use caution when viewing an eclipse.

The only real safe way to look at a partial eclipse is by using approved solar eclipse viewers. These special-purpose filters, which are often known as “eclipse glasses,” must meet international standard ISO 12312-2 to ensure safe viewing. Any other viewer – sunglasses, telescopes, smoked glass, binoculars, and polarized filters – is not safe.

Now, if eclipse glasses are not available, you can build your own viewer, often called a pinhole camera or pinhole projector. Luckily, these are very easy to make with common household items. First, cut a one-inch square hole in the middle of a piece of cardstock. Then, tape a piece of aluminum foil over the hole. Once it’s secure, use a pin to poke a small hole in the aluminum foil. To use your projector, place a second piece of cardstock on the ground and hold the piece with aluminum foil above it, with the foil facing up. Stand with your back to the sun and view the projected image on the cardstock below you – the farther away you hold the paper, the bigger the projected image will be.

Be Safe, Make Memories

To be clear: staring at the sun under any circumstances is bad for the eyes. The upcoming eclipse will be viewable by 500 million people across North America, but only about 12 million live in the path of totality, so it’s important for Americans to understand how to view the eclipse safely. Only within this path – and only once the sun is completely blocked by the moon – can viewers safely look at the eclipse without protection.

If you have discomfort or problems with your vision after the eclipse, visit us for a comprehensive eye exam. If you plan ahead and use caution, however, you can prepare yourself for one of nature’s most beautiful spectacles. Enjoy the view!