Expert tips for viewing the solar eclipse

The next solar eclipse will happen on Monday, April 8. Viewers in the path of totality will be treated to up to 4 minutes and 28 seconds of uninterrupted darkness when the moon fully covers the sun. But the sun can do serious damage to your eyes even when it’s partially blocked by the moon, says Dr. Amol Kulkarni, ophthalmologist and retina specialist at SSM Health Davis Duehr Dean Eye Care.

“Due to the dimming light in the sky, you may be tempted to look directly at the eclipse, but the sliver of radiation peeking past the moon is still enough to cause permanent damage to your retinas,” Dr. Kulkarni explains.

So how can we protect our eyes while still enjoying the solar eclipse?

“The only safe way to look directly at the uneclipsed or partially eclipsed sun is through special-purpose solar filters available as eclipse glasses or handheld solar viewers,” Dr. Kulkarni said.

What to look for in eclipse glasses

Eclipse glasses are different from your everyday sunglasses; they’re at least 1,000 times darker!

Safe eclipse glasses or viewers should be marked as meeting the ISO12312-2 (sometimes written as ISO 12312-2:2015) international standard to ensure they provide the correct amount of filtering of the sun’s rays. Filters that are ISO 12312-2 certified not only reduce visible sunlight to safe and comfortable levels but also block solar UV and IR radiation.

Aside from checking the ISO standard, Dr. Kulkarni says you should also consider the following when it comes to safety:

• If the filters are torn, scratched, or punctured, discard them.
• If the filters are coming loose from their cardboard or plastic frames, discard them.
• Read and follow any instructions printed on or packaged with the filter.
• Always supervise children using solar filters to be sure they don’t remove them.

Things to avoid during the eclipse

• Do not look at the sun through a camera, telescope, binoculars or any other optical device while using your eclipse glasses or hand-held solar viewer. The concentrated solar rays will damage the filter and enter your eyes causing serious injury.
• Do not use homemade filters. Seek expert advice from an astronomer before using a solar filter with a camera, telescope, binoculars or any other optical device.

“Homemade filters may seem like they dim the sun to a comfortable level, but that doesn't mean they do so across the whole electromagnetic spectrum,” Dr. Kulkarni said. “While you're enjoying a ‘comfortable’ view of the dim sun, solar infrared radiation could damage your vision permanently.”

• Do not rely on regular sunglasses. Regular sunglasses, no matter how dark, are not safe for viewing the sun.

The next full solar eclipse won’t happen again in the United States until August 2044. With the right eye protection, viewing this year’s eclipse can be an exciting and rare experience.

SSM Health Eye Care providers are happy to help with your family’s eye care needs. Our team provides a full range of services, including routine eye exams, prescription eye-glasses and contacts, and LASIK surgery. Find a location near you.