On August 21, millions of people within a 112km wide corridor will be able to view a total solar eclipse as it traverses across the continental USA. In our area, the eclipse will reach about 90% totality, known then as a partial eclipse, at approximately 10:20 am. While not an unusual worldwide occurrence, safely viewing this phenomenon presents unique and important considerations.
Most of us know that it is unsafe to view the sun and under normal circumstances, it is difficult to look at the sun long enough to incur damage because of our natural aversion reflex. “We learn early on in life we just shouldn’t be looking at something that bright because it is uncomfortable and we can’t see anything,” says Dr. Ralph Chou, our past university professor and renowned expert in the field of vision safety. With a partially eclipsed sun, the danger occurs when temptation overrides both common sense and this protective reflex, also because it can be viewed without the same level of discomfort.
Even when the sun is almost completely covered, the tiny crescent that remains is still bright enough to literally burn your retinas and create a condition known as solar retinopathy. When intense solar radiation hits the retinas, thermal damage and even destruction of those cells may occur. This damage occurs without any sensation of pain since the retina does not have pain receptors. The injury can be temporary or permanent and risks long-term or even permanent vision loss.
If you’re planning on watching this event, here are some critical points to keep in mind:
- Homemade filters or ordinary sunglasses, even very dark ones, are not safe for looking at the sun.
- FACT: Special-purpose solar filters are about 100,000 times darker than ordinary sunglasses
- The only safe way to look directly at the uneclipsed or partially eclipsed Sun is through special-purpose solar filters (eclipse glasses or handheld viewers) that meet international standards for such products.
- Eclipse Live Stream, a mega-cast hosted by NASA on the day, will be a great way to safely view the eclipse from unique, multiple coverages including space aircraft, high altitude balloons, and the International Space Station
“How to View the 2017 Solar Eclipse Safely“ (http://bit.ly/2t6WUjG) is a 1-page flyer written by the Solar Eclipse Task Force and provides further detailed information. This flyer, along with other useful eclipse resources, is available at our Eye Design Optometry offices, where we are committed to helping you protect the Future of your Vision.