Why do you need glasses to prevent permanent eye damage during eclipse?

AUSTIN (KXAN) — We’re less than a day away from the first of two solar eclipses over the next few months.

On Oct. 14, an annular eclipse will briefly dim the skies over sections of the western U.S. and Central and South America. Viewing the eclipse safely will require some prep on your part, however.

“(I see) a few patients a year that have either accidentally looked at the sun or were trying to view an eclipse,” said Dr. Andrew Neighbors, a Seattle-based optometrist.

According to Neighbors, damage caused by looking at the sun during an eclipse is called eclipse blindness or solar retinopathy. This damage may heal over time but could be permanent. Neighbors said there is little that can be medically done to repair this damage.

What happens during eclipse blindness?

Eclipse blindness appears as a black dot in your vision, Neighbors said.

“If you’ve ever seen a car headlight or something like that, it’s really bright, and then afterwards, you can kind of see the car headlight. It would be like that. It just wouldn’t go away,” Neighbors said.

Viewing an eclipse without protection can cause the sun’s rays to focus on your retina and burn it. (Credit: Eric Henrikson/KXAN)

The sun causes this by burning a spot on your retina.

“Have you ever used a magnifying glass with the sun and you can literally start a fire?” Neighbors asked, saying that when looking at the sun, your eye’s lens acts like the magnifying glass. “You’re focusing a light. You’re literally burning your retina.”

With no pain receptors there, you won’t even feel your retina sizzling.

“If afterwards you notice a spot or loss of central vision — anything that lasts longer than a few minutes — you’ll want to make sure you come in and visit your optometrist … so that they can check it out,” Neighbors said.

Preventing eclipse blindness

The American Optometric Association recommends that everyone use certified solar eclipse glasses to view an eclipse. These glasses cost about $1 and are typically made of paper and have a dark film covering the eyes.

“It’s a very, very dark piece of film,” Neighbors said. “ISO 12312-2 is the international standard [of the film].”

Eclipse glasses prevent your eye from absorbing most of the sun’s light, allowing you to view an eclipse safely. (Credit: Eric Henrikson/KXAN)

Neighbors said you will know the glasses are legitimate because they will have the letters ISO on them, and they will also be nearly impossible to see through. He said you will only be able to see the sun through them. Regular sunglasses will not work.

“Make sure that you put them on before you look up,” Neighbors recommended.

Proper eye protection is needed throughout the eclipse, from the initial partial phase to the ring of fire to the final partial phase.

Annular eclipse

Saturday’s eclipse is an annular eclipse. Occurring three times a year, annular eclipses occur when the moon is further from the Earth and doesn’t completely block the sun.

What’s called a “ring of fire eclipse” will briefly dim the skies over parts of the western U.S. and Central and South America. A bright, blazing border will appear around the moon for as much as five minutes, wowing skygazers along a narrow path stretching from Oregon to Brazil.

The celestial showstopper will yield a partial eclipse across the rest of the Western Hemisphere.

It’s a prelude to the total solar eclipse that will sweep across Mexico, the eastern half of the U.S. and Canada, in six months.

You will need to hold onto your glasses for this eclipse, too.

Unlike Saturday, when the moon is too far from Earth to completely cover the sun from our perspective, the moon will be at the perfect distance on April 8, 2024.

The Associated Press contributed to this report.