North Dakota won’t be in the path of the total phase of Monday’s solar eclipse, but sky watchers still need to follow safety guidelines to avoid severe damage to their eyes.

A partial solar eclipse will be visible to North Dakotans around midday on Monday, with the maximum eclipse occurring just before 1 p.m.

The American Optometric Association says the only safe way to view a partially eclipsed sun is through special solar filters, such as eclipse glasses that meet international ISO standards. Sunglasses, smoked glass, telescopes, magnifiers, or polarizing filters are unsafe, according to the AOA, which adds that if you can’t find approved eclipse glasses, the best way to view it is to create a pinhole projector to watch the eclipse indirectly.

Trinity Health optometrist Jill Martinson-Redekopp, OD, says looking at a partially eclipsed sun without the recommended protection can result in permanent eye damage.

“The reason it’s so dangerous is that the sun’s rays are more intensive as the moon starts to cross over the sun, and the intensity of the ultraviolet rays causes physical damage to the retina, like a burn. Once that damage is done it’s permanent. People don’t feel it, so it’s silent damage,” Dr. Martinson-Redekopp said.

Retinal damage can appear as a central blind spot in a one’s vision, which mimics what patients experience when they have macular degeneration. Dr. Martinson-Redekopp adds that there’s a misperception that cameras with sun filters are safe, but they actually intensify the sun’s rays even more.

“The safe method, assuming you have eclipse glasses that are truly ISO-compliant, is to avoid any steady viewing. Look at it for 10 seconds with the glasses and then look away for several minutes. Safer still is the pinhole method, which projects the image of the eclipse on a surface.”

The American Astronomical Society has warned eclipse enthusiasts to be on the lookout for counterfeit eclipse glasses. It suggests that you check the society’s list of reputable vendors on its website, aas.org.