North Bend doctor offers advice, solar filters, for safely watching solar eclipse Aug. 21,

Next Monday, at about 10:21 a.m., nighttime will descend on the Valley, for about two minutes. This remarkable event is the first solar eclipse to be visible in the United States since Feb. 26, 1979, an event that will, in full, take roughly two and a half hours, as the moon crosses the face of the sun, obscuring up to 92 percent of it for those of us watching in the Valley.

With the exception of a 2024 eclipse that the National Aeronautics and Space Administration is projecting to be visible in the central and eastern half of the U.S., this eclipse is a once-in-a-lifetime opportunity for many people.

It’s an opportunity you need to prepare for, though.

“People know ‘well, I shouldn’t stare at the sun’ but people don’t know how long is safe and ‘well maybe I’ll just sneak a look,’” Duvall said last week. He’s been getting many questions from the community about the big event.

“Staring at the sun is bad, period,” he said, whether it’s during a normal day, one of last week’s smoky sunsets, or a solar eclipse. “In an eclipse, the rays of the sun are no less damaging than when there’s not an eclipse, except the eclipse allows you to stare longer.”

The clinic has purchased more than 400 pairs of solar eclipse viewers — think cardboard 3-D glasses, but covered with a thick foil instead of red and blue plastic — to give to community members who ask for them.

“They’re disposable… but the protection in them is not low-technology,” said Duvall.

They’re what he’ll be wearing next Monday morning when the eclipse happens, too.

According to NASA’s Eclipse 101 page, the eclipse will be visible starting at 9:08 a.m. for this region. The complete obscuring of the sun, or totality, will last from 10:19:36 to 10:21:38, and the eclipse will be over by 11:42.

Eye safety

For that period of time, Dr. Duvall offers this:

A solar eclipse occurs when the moon blocks out any part of the sun; here the solar eclipse will take about two to three hours, from beginning to end.

The American Astronomical Society offers a good map and chart showing the times that U.S. citizens will be able to view the eclipse.

According to NASA, anyone within the path of totality stretches from Lincoln Beach, Ore. to Charleston, S.C., will be able to see the total solar eclipse. In this path, and only during the short phase of complete totality lasting just over two minutes, is the one time it can be safe to look at the sun.

Anyone outside of this path, including us in the Snoqualmie Valley, will still be able to view a partial solar eclipse, weather permitting. In those areas of partial eclipse, there is no safe time to look at the sun directly with the naked eye. You must protect your eyes while watching the entire eclipse.

Staring at the sun can damage the back of your eye, a condition known as solar retinopathy, which can permanently damage vision or even cause blindness.

There is only one safe way to look directly at the sun, whether during an eclipse or not: through special-purpose solar filters. These solar filters are used in “eclipse glasses” or in hand-held solar viewers. They must meet a very specific worldwide standard known as ISO 12312-2.

Ordinary sunglasses, (even very dark ones), homemade filters, smoked glass, welding shields, unfiltered telescopes or magnifiers, and polarizing filters are not safe for looking at the sun.

Also, there have been reports of inferior and counterfeit eclipse viewers being distributed. To date only four manufacturers have certified that their eclipse glasses and handheld solar viewers meet international safety standards: Rainbow Symphony, American Paper Optics, Thousand Oaks Optical and TSE 17.

If you are unable to get appropriate eclipse viewers, you can use or build a pinhole projector to watch the eclipse with these instructions: https://eclipse2017.nasa.gov/2d3d-printable-pinhole-projectors.

Steps to follow for safely watching a solar eclipse:

• Carefully look at your solar filter or eclipse glasses before using them. If you see any scratches or damage, do not use them.

• Always read and follow all directions that come with the solar filter or eclipse glasses. Help children to be sure they use handheld solar viewers and eclipse glasses correctly.

• Before looking up at the bright sun, stand still and cover your eyes with your eclipse glasses or solar viewer. After glancing at the sun, turn away and remove your filter—do not remove it while looking at the sun.

The only time that you can look at the sun without a solar viewer is during a total eclipse. When the moon completely covers the sun’s bright face and it suddenly gets dark, you can remove your solar filter to watch this unique experience. Then, as soon as the bright sun begins to reappear very slightly, immediately use your solar viewer again to watch the remaining partial eclipse.

Never look at the uneclipsed or partially eclipsed sun through an unfiltered camera, telescope, binoculars or other similar devices. This is important 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 your eyes.

Talk with an expert astronomer if you want to use a special solar filter with a camera, a telescope, binoculars or any other optical device.

“The upcoming solar eclipse is an incredible astronomical happening,” says Dr. Duvall, “and a rare shared experience with others in our community and across the country. We want people to be safe while enjoying this special event.”

If you do experience discomfort or vision problems following the eclipse, visit your eye doctor.

Here’s to safe viewing of an amazing natural phenomenon!

Last week, Dr. Duvall also discussed the effects of staring at the sun, which typically include eye pain, temporary changes to color vision, and blurred vision. Some patients, depending on their exposure, can develop schitomas, which Duvall described as “a little hole in the center of your vision where the retina was damaged.”

“Within the retina, you get a photochemical toxicity, and it just takes time for that to recover,” said Duvall, “anywhere from a couple of days to a couple of weeks.”

For more information about watching the eclipse, see:

• American Optometric Association – www.aoa.org

• American Academy of Ophthalmology – www.aao.org

• The American Astronomical Society – https://eclipse.aas.org/eclipse-america/when-where

• NASA’s Eclipse 2017 – https://eclipse2017.nasa.gov

• STAR_Net – https://www.starnetlibraries.org/2017eclipse