Just received this email from a local optometrist:
The Right Way To Watch The Solar Eclipse
On Monday, August 21, 2017, many of us in the United States will experience the first total solar eclipse in 38 years. Few people were lucky enough to see the last total eclipse as it was visible in only five states; the 2017 eclipse will be visible across 12 states – from Oregon to South Carolina. What should you expect on August 21, and how will watching it affect your vision?
What Will Happen
A solar eclipse occurs when the moon passes between Earth and the sun. The moon will cover at least part of the sun for two to three hours, with the moon blocking the sun completely for no more than three minutes. The temperature will likely drop about 10 degrees and, in areas under this shadow, day will turn into night.
Where It Will Happen
You won’t necessarily be able to look outside your window and suddenly see darkness. Those living within the “path of totality,” or the 70-mile-wide, 3,000-mile-long area that will lie in the moon’s shadow, will have the best view of the total eclipse. People outside of this area will see a partial eclipse, where the moon covers only some of the sun. Approximately 12 million people live within the path of the total eclipse, while another 7 million are expected to travel to those areas to enjoy the moment.
Protecting Your Vision
Here are a few tips for protecting your vision during this rare and visually mesmerizing moment in nature:
- Regular sunglasses aren’t enough protection during an eclipse. Some companies offer “eclipse viewing glasses” or other eye gear specifically designed for watching the eclipse, which can make viewing the event safer for your vision.
- If you’re considering buying eclipse glasses or solar viewing cards, make sure they’re marked with ISO 12312-2, which is the universal standard for safely blocking solar UV and IR radiation.
- The weather during the eclipse may impact its visibility, but even in cloudiness, it’s never safe to stare directly into the sun, especially without any UV protection.
- Be sure to avoid using binoculars, exposed film, smoked glass, polarizing filters or any other objects that might “dim” the sun, but not protect against solar radiation.
On August 21, your eyes will likely see an incredible sight, but take extra care of your vision to experience it safely. Talk with your eye doctor if you have any questions about protecting your eyes during (or after) the eclipse.
Disclaimer: This advice is general in nature and does not constitute an exam. For specific advice, see your eye doctor or healthcare professional.
(Sources: Astronomy Magazine,
http://cs.astronomy.com/asy/b/astronomy/archive/2014/08/05/25-facts-you-should-know-about-the-august-21-2017-total-solar-eclipse.aspx; AOA,
https://www.aoa.org/patients-and-public/caring-for-your-vision/2017-solar-eclipse?sso=y; Conde Nast,
http://www.cntraveler.com/story/why-you-should-plan-a-trip-now-to-see-the-2017-solar-eclipse; AAS,
https://eclipse.aas.org/eye-safety/iso-certification; The Washington Post,
https://www.washingtonpost.com/news/speaking-of-science/wp/2017/07/21/a-total-solar-eclipse-is-happening-aug-21-and-heres-what-you-need-to-know/?hpid=hp_hp-more-top-stories-2_eclipse-930a:homepage/story&tid=a_inl&utm_term=.9dc1541e9dd5)