Catching a glimpse of Monday’s rare solar eclipse can be exciting – but can cause lasting vision damage without proper safety precautions, say faculty members at Ferris State University’s Michigan College of Optometry. 

“Unsafe viewing of the sun, even for a few seconds, is not worth a lifetime of vision impairment,” said Dr. Eric Syverson, an MCO assistant professor and chief of Medical and Surgical Services.

A rare total solar eclipse will be visible across parts of the United States, Canada and Mexico on Monday, April 8.  A total solar eclipse happens when the moon passes between Earth and the sun – blocking the sun’s light and darkening the sky as if late in the evening or early in the morning.

As cool as a rare solar eclipse is to observe, Syverson strongly urges skywatchers to carefully use special eye protection and limit even protected exposure to minimize the risk of eye damage.

“Some may say it is safe to remove solar viewing glasses to look directly at the total eclipse. Theoretically, this has some merit, but I would not recommend taking that chance,” he said.

Syverson recommends purchasing certified solar viewing glasses that meet the requirements of the International Organization for Standardization (ISO 12312-2). He further suggests Certified Solar Viewing Glasses with an ISO logo and reference number 12312-2.

Preparation matters.

“These glasses are designed to ensure that solar viewing glasses provide adequate protection for the eyes when looking at the sun or a solar eclipse,” Syverson said. “They are not expensive, but I recommend ordering them ahead of time. They can be found online.”

Syverson said pinhole projectors or indirect viewing methods, as recommended by the American Optometric Association, are also recommended. He also noted that the total solar eclipse can be viewed via the NASA live stream. Additionally, NASA offers eye safety tips for viewers.

Syverson has safety reminders for casual viewers:

• Normal sunglasses do not have the required optical density or transmission requirements to protect your eyes against the sun’s harmful rays.
• Supervise and educate children on the harm of looking directly into the sun.
• Homemade filters should not be used.
• Limit your viewing of the total eclipse even with the proper safety equipment.

The consequences of not exercising caution in viewing the total solar eclipse could be significant, including the possibility of permanent vision loss and impairment due to solar retinopathy, which is damage to the retina - the back of the eye -- from harmful sun rays. 

Other potential consequences include red, irritated and or painful eyes due to solar keratitis, which he likened to a sunburn on the cornea that can be painful and difficult to treat.

NASA’s quick facts include the corona, the sun’s outer atmosphere, being normally not visible. During a total solar eclipse, however, the corona becomes visible and provides an opportunity to study this aspect of the sun.

Also, according to NASA, the next total solar eclipse visible from the contiguous United States is not expected until Aug. 23, 2044.

The MCO faculty and staff encourage viewers to protect their vision while observing this unique natural phenomenon.

Ferris State’s Michigan College of Optometry, founded in 1974, is the only optometry program in the state. It includes the University Eye Center, a full-service eye care clinic serving university employees, students, and the surrounding community. In addition to providing comprehensive care, the center has specialty clinics in ocular disease, pre- and post-surgical care, specialty contact lenses, pediatrics, and binocular vision and vision therapy. 

*Image provided by Ferris State University.