The countdown is on! There are now only four days until the total solar eclipse and if you want to watch the moon cover the sun you need to wear protective glasses, but they can be hard to come by.

Experts say looking at the sun can cause permanent damage to your eyes even during a solar eclipse so to watch safely you need protective glasses. The problem is solar glasses are flying off the shelves.

CBS 58 called called Best Buy Thursday morning and they said all of their Wisconsin stores are sold out. And that's not unique to Best Buy, many other retailers like Walmart, Lowes and Toys R US are also sold out.

Your normal sunglasses are not safe for viewing the eclipse.

PhD physics student from UW-Milwaukee Kristina Islo says, "What they do is they block out a significant portion of the sunlight. So I think they transmit only about 0.00032 percent of the actual sunlight and that's a safe amount of sunlight for you to look at."

If you're on the hunt for solar glasses, UW-M Planetarium will have 200 glasses for sale during their viewing event from 11 AM to 3 PM on Monday.