Top 5 ways to help your patients safely view the solar eclipse

On Monday, August 21, 2017, star gazers and sky watchers worldwide will have their eyes fixed to the sky as they try to catch a glimpse of the Great American Solar Eclipse-the first of its kind since June 8, 1918. This year’s total solar eclipse roughly follows the same path as the one in 1918 crossing the U.S. from Washington state to Florida.

Viewing the solar eclipse is a rare, exciting experience, but patients should be warned of the dangers they face if they don’t view it with the appropriate tools.

“The first rule is that this is a potentially dangerous event,” says Optometry Times Editorial Advisory Board Member Leo Semes, OD, FAAO. “It could cause permanent damage to the eye.”

Solar retinopathy, or photic retinopathy, can occur when a person stares at the sun, causing damage to the retinal tissue at the fovea and resulting in a mild-to-moderate visual acuity deficit and central or paracentral scotoma.

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"Eclipse retinopathy is a unique form of solar retinopathy that results from retinal and macular damage sustained during solar eclipse viewing," says James F. Hill, OD, FAAO, of Johns Island, SC. "Damage from solar retinopathy can occur without any feeling of pain and the visual effects are not noticed for several hours after the damage has been done. There is no treatment for solar retiopathy."

Optometry Times Editorial Advisory Board member Dori Carlson, OD, FAAO, has seen a patient with eye damage caused by viewing a solar eclipse with no eye protection.

“Before I had a retinal camera or an optical coherence tomography (OCT), I had an older female patient with best corrected vision of 20/30,” says Dr. Carlson. “She had a strange crescent-shaped scar in the macula of each eye. When I talked to her about it, she told me she had watched a solar eclipse without eye protection when she was a little girl and her vision was never as good after that event.”

With stories like the one from Dr. Carlson and the media and public in a frenzy over this year’s historic event, Optometry Times sought out methods to see the eclipse, along with tips to view it safely.

Here are the top five ways to advise your patients on how to view the total solar eclipse from their own backyards using direct or indirect viewing.

Click here for the top 5 ways to help your patients safely view the solar eclipse

1. Solar shield (direct method)

“Appropriate solar shields made for eclipse viewing are safe and effective for direct viewing of the solar eclipse,” says Jessica Haynes, OD, FAAO, of Germantown, TN. “These devices should be clearly labeled as safe for direct sun viewing.”

Solar shields should not be confused with “solar shield” fitover or wraparound sunglasses, which are not safe for viewing the solar eclipse, says Dr. Haynes.

The Eclipse Shades Solar Shield uses polymer filters to transmit a truer light orange image of the sun when viewing the solar eclipse. The lens is mounted inside of a laminated board holder with a viewing opening of 2 inches by 4 inches.

Related: Sunlight and its effect on eye health

Another solar shield option is a welder’s shield, which is a piece of glass that fits into the front of a welder’s helmet to protect the eyes.

“Three decades ago there was a total solar eclipse that was centered near Birmingham, AL, and my friends wanted to know how to look at it directly,” says Dr. Semes. “Of course, the guidance was to use an indirect method. My research led me to suggest a No. 12 welder's shield to appropriately attenuate the solar intensity. To be safe, we used a No. 14, which is now part of a recommendation from the National Aeronautics and Space Administration (NASA).”

Welder’s shields can be purchased from a welding supply store and are roughly 2 inches by 6 inches.  For eclipse viewing, this item must be held close to the eyes, says Dr. Semes.

Up next: Eclipse glasses (direct method)

2. Eclipse glasses (direct method)

Eclipse glasses are designed for safe direct solar viewing of solar eclipses, sun spots, and other solar phenomena.

“Like solar shields, eclipse glasses are specifically designed to adequately block light rays and make direct eclipse viewing safe,” says Dr. Haynes. “Both solar shields and eclipse glasses should be inspected for scratches and defects prior to use.”

Remind patients to fully avert their views away from the eclipse before removing eclipse glasses, says Dr. Haynes.

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“One potential risk is glasses that offer a partial eclipse view,” says Dr. Semes. “Not much is written about this, but there is a real danger to viewing a solar eclipse directly without appropriate protection. There is also an international standard that address direct sun viewing- International Organization for Standardization (ISO) 12312-2.”

Devices that are compliant with the ISO 12312-2 safety standard may be used to look at the uneclipsed or partially eclipsed sun through them without time limits.

Up next: Lens solar filters (direct method)

3. Lens solar filters (direct method)

Lens solar filters can be applied to telescopes and binoculars for safe eclipse viewing. The purpose of the lens filters is to keep the sun’s heat and light out of the optics.

“You should never look at the eclipse through a telescope or binoculars without appropriate solar filters applied to the larger lens,” says Dr. Haynes. “Do not view the eclipse with telescopes or binoculars over your eclipse glasses or solar shields, either.”

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Three of the most common lens solar filters are:

• Aluminized Mylar

• Black polymer

• Metal on glass

Some filters display the sun as white, while others show an orange, yellow, or bluish tint.

Dr. Semes cautions patients from using homemade lens filters.

“Homemade filters consisting of unexposed X-ray film are potentially hazardous,” he says.

Up next: Pinhole camera (indirect method)

4. Pinhole camera (indirect method)

Creating a pinhole camera can be accomplished with a few simple supplies you found at home, office, or school.

“The eclipse can be safely viewed indirectly with the pinhole method,” says Dr. Haynes. “With this method, you do not directly look at the sun but instead view a projected image of it created by a pinhole, making it a safe method.”

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NASA provides instructions on how to create a pinhole camera with:

• Two pieces of white card stock

• Aluminum foil

• Tape

• Pin or paper clip

“This is a popular grade-school project to avoid any possibility of direct viewing among youngsters,” says Dr. Semes. “The pinhole focuses the eclipse image onto a screen, obviating the need to even be tempted to look at the eclipse directly.”

Up next: Pegboard/straining spoon method (indirect method)

5. Pegboard/straining spoon method (indirect method)

Eclipse viewers can also use the pegboard/straining spoon method to view the eclipse indirectly.

This is also a safe and fun way to appreciate the solar eclipse without directly looking at it, says Dr. Haynes.

“With your back to the sun, use a pegboard, straining spoon, or similar object to project the sunrays on a white wall or the pavement,” says Dr. Haynes. “With this method, you will see multiple projected images of the sun.”

As the eclipse passes, the sun will appear as a crescent during the partial phases of the eclipse.

“The solar eclipse has created quite a stir around the U.S.,” says Dr. Carlson. “We have friends who have rented a house in Missouri so they can watch the total eclipse. In our office, we’ve been handing out fact sheets and distributing solar eclipse glasses to our patients.”

Related: Sunwear and the science of light

Handing out fact sheets and educating patients of the dangers of viewing the solar eclipse can go a long way in preventing irreversible eye injuries.

Outside of using these five methods, Dr. Haynes says to also follow these three tips:

• The only time that direct viewing of the eclipse without appropriate filters is safe is during the brief time of totality

• Not all eclipse glasses and solar shields on the market are created equally. Advise your patients to look for glasses that meet the ISO safety standards for eclipse viewing. These glasses should be labeled with the ISO label and reference number 12312-2.

• Even the darkest of ordinary-wear sunglasses do not provide appropriate filtration of harmful ultraviolet and infrared rays. Unsafe eclipse viewing without appropriate, approved filters can lead to permanent visual damage.

If your patients are interested in more information, direct them to these websites:

• https://www.aoa.org/patients-and-public/caring-for-your-vision/2017-solar-eclipse?sso=y

• https://eclipse2017.nasa.gov/safety

• https://www.space.com/35555-total-solar-eclipse-safety-tips.html

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