Eclipse glasses: What's the big deal?

Published: Aug. 11, 2017 at 1:05 PM CDT
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If you're planning on taking in this unique astronomical event on August 21 you will need to purchase a pair solar eclipse glasses. Directly viewing the eclipse with no eye protection can cause irreversible damage.

Optometrist Dr. Brad Moriarty explains, “retinal burns can happen very quickly with looking at the sun, even during eclipse, even at the maximum part of the eclipse where there's only a little bit of sun showing. Just a few seconds can burn the retina.” The typical human instinctual response is to quickly look away before any severe damage has actually occurred.

You won’t notice the burns right away but a few hours later. You’ll have a blurred spot in the center of your vision that will get bigger and turn black. The vision loss is irreversible but treatment can help limit the size of the spots.

In Rapid City, at the maximum extent of the eclipse, the sun will be 96% covered. This will be from 11:48 to 11:52 a.m. You must wear the glasses for the entirety of the event. Even with 4% of the sunlight getting through, you can still burn your eyes very quickly.

If you will be traveling to the path of totality in Nebraska or Wyoming, you may look at the sun without your glasses ONLY during the time of totality (roughly two minutes and 30 seconds). Eclipse chaser Peggy Norris explains how you know when it’s time to remove your glasses:

“Just as it goes total you get what’s called a diamond ring effect and it actually looks like a diamond ring just as that last tiny bit of light comes through. When you see the diamond ring you can take off your eclipse glasses and then you’ve got the two and a half minutes. Then you see the next diamond ring and you put them back on again.”

Make sure you look closely before purchasing eclipse glasses. They must be ISO certified to properly protect your eyes. For a list of reputable vendors, check out NASA’s list


Glasses that meet the ISO international safety standard not only reduce visible sunlight to safe and comfortable levels but also block ultra violet and infrared radiation. Also check the lenses carefully to ensure there are no holes or scratches.

Sunglasses are NOT safe for looking directly at the sun. Sunglasses typically let in 10 to 20% of daylight. Eclipse glasses are 100,000 times darker, letting in 0.0003% and are the only way to look right at the sun without harming your eyes.

There is a way you can indirectly view the eclipse using a pinhole projector. See the video below for an easy way to make one using a cereal box, paper and a piece of tin foil.

Eclipse glasses vendors in Rapid City

(Be advised that some of these locations may be sold out):

- Walmart Optical

- Who's Hobby

- Common Cents

- Lowes

- The Journey Museum

- Rapid City Public Library

- Menards

- K Mart

- Albertsons

- (Many local eye doctors also have glasses available)