Protect your eyes during the solar eclipse

For the first time in nearly 100 years, a total solar eclipse on August 21 will darken the skies across the continental United States. But viewing this once-in-a-lifetime event without the proper eye protection is not a good idea.

“It’s unsafe to look at the sun with your naked eye—or with conventional sunglasses, a smartphone, binoculars, or a telescope,” according to Rajesh Rao, MD, retinal surgeon and assistant professor of ophthalmology and visual sciences, University of Michigan Kellogg Eye Center in Ann Arbor, MI.

“As doctors and ophthalmologists, we want to make sure everyone is taking proper precautions. We know there’s a lot of excitement. People want to look,” he added.

Retinal damage can be caused by specific wavelengths of light in sunlight. The fovea, specifically, can be damaged, and this damage could cause a partial retinal hole or solar retinopathy depending on the length and extent of exposure.

Staring at the sun, for even a short time, can cause temporary and even permanent vision damage. Ordinary sunglasses, and camera and telescope lenses will not properly protect the eyes. To view the total eclipse, specially designed glasses, viewers, and lens filters are necessary.

The phase of the eclipse should dictate when these lenses are necessary, according to Dr. Rao. During totality, the sun’s face will be completely covered by the moon and the sky will be darkest (total eclipse). This phase will last less than 3 minutes, and is safe to view without solar filters.

Before and after this total eclipse, the moon will block the sun’s face only partially (partial eclipse). It is during the partial eclipse that solar filter lenses should be used, without exception.

“The moment it becomes a partial eclipse again, you have to put them on again,” said Dr. Rao.

The total solar eclipse will only occur on a 70-mile wide path that stretches from Oregon to South Carolina. All others not in this path will see only a partial eclipse. For these people, there will be no safe time to remove protective lenses.

For those who want to purchase specially designed glasses, only the ones with an ISO 12312-2 designation have met international safety standards. For a list of approved brands, go the American Astronomical Society’s site: https://eclipse.aas.org/resources/solar-filters.

Be sure to discard even approved lenses with any surface scratches.

Enjoy the eclipse. But, be sure to take the necessary steps to protect your eyes.

“Our main goal is that you enjoy this once- or twice-in-a-lifetime opportunity while protecting your eyes from a substantial chance of vision loss or blindness,” concluded Dr. Rao.