The Solar Eclipse and Eye Safety

Don't be "Blinded By The Light!"

Like the rest of the nation, Chester County will get a glimpse of a much-anticipated solar eclipse on Monday, August 21. It’s the first to cross from west to east over the United States since June 8, 1918 – almost a century ago.

The eclipse will take place at approximately 2:43 PM, when the moon’s path puts it in a position to obscure most or all of the sun (depending on where you are) for less than 3 minutes. The best place to “view” the total eclipse will be in … Oregon, then Idaho, Wyoming, Nebraska, Missouri, Kentucky, Tennessee, and finally South Carolina. These states and a few others are in the direct path of total obscuration (also known as “totality” when the entire circle of the sun is darkened). In the Delaware Valley, the moon will block about 75% of the sun, according to the U.S. Naval Observatory; in other words,  we are not in the path of totality.

Amateur astronomers everywhere have been scrambling to purchase special solar eclipse glasses so they can safely view this rare celestial phenomena. These special glasses – some of which look like they type you’d get at a 3D movie – block out all UV rays and nearly all visible light, because they are 100,000 times darker than sunglasses. 

Show of hands. Did you buy the glasses? If so, buyer beware. According to the American Astronomical Society, the marketplace has been flooded by knock-off eclipse glasses that are erroneously labeled “ISO compliant” (ISO is the International Organization for Standardization), when actually many are not. If you purchased glasses, here is the AAS list of reputable vendors of solar filters and viewers.

What if you didn’t buy the right glasses? How do you view the eclipse now that you’ve missed the delivery window for online retailers and local stores are out of stock?

“It’s simple,” says Dr. Richard Donze, Senior Vice President for Medical Affairs at Chester County Hospital, “just don’t look at it. Basically, without the ISO certified glasses or viewers, there’s not a 100% safe way to look at the sun from Chester County’s viewpoint, especially since there won’t be totality here. Do what your mother, your father, your teachers (and even Seinfeld in one episode) always taught you, don’t look at the sun … ever. This well-known life lesson will still be true on Monday.

As tempting as it may be to check it out, looking at the eclipsed sun without legitimate ISO-certified eyewear has the potential to cause serious eye damage called Solar Retinopathy. By comparison, it is as intense as staring at the light of a welder’s torch. It can cause similar damage, which is why welders wear highly protective masks.

Solar Retinopathy is damage that occurs because the sun’s light enters the eye allowing the harmful UVB rays to first destroy the eye’s protective surface (cornea) and then the UVA rays to damage the lens and finally harm the retina and macula in the back of the eye. This type of injury can cause blurred vision, dark spots, pain in bright light, or loss of vision in the center of the eye. Permanent eye damage can occur in less than 100 seconds.

“It’s just not safe,” reminds Dr. Donze. “Why risk permanent eye damage?”

Here are a few other Eclipse Do’s and Don’ts:

• Don’t look at the sun wearing everyday sunglasses.
• Don’t look at the sun through binoculars or a telescope.
• Don’t look at the sun through a reflection, such as a mirror or body of water. The light is still strong enough to cause eye damage.
• Don’t look at the sun through clouds or fog. They don’t decrease the brightness enough.
• Don’t look at the sun through your ISO-certified eclipse glasses if there are any scratches or damage. (Follow the directions carefully).
• Don’t remove your eclipse glasses at any point since the moon will not provide a total eclipse in the Chester County area.
• Don’t forget to protect the eyes of your young children and pets.
• Do call an ophthalmologist or optometrist if you experience any symptoms that might be related to sun-induced eye damage.
• More Tips >>

And, here’s our best tip for safely viewing the solar eclipse: Watch it on TV or online. NASA will be live streaming the 100-minute coast-to-coast path of the eclipse starting at 12 PM, giving Chester County residents a safe way to watch it without harming their eyes.