Pizza Hut came up with a clever way to turn a pizza box into a solar eclipse viewer

To safely watch the total solar eclipse on August 21 without damaging your eyes, you'll need certified eclipse glasses — or a pizza box.

In a new video, Pizza Hut demonstrates how to turn an empty pizza box into a viewer that will let you watch a projection of the eclipse.

To make it, you will need a cardboard pizza box, foil, scissors, pen, tape and a sheet of white paper. First, detach the two sides of the box from each other.

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Next, cut a small hole in the center of the pizza box's top, tape a square piece of foil over it, and poke a tiny hole in the foil.

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Lastly, tape the piece of paper to the interior of the other side of the box.

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To watch a projection of the eclipse, stand with the sun behind you, with the tin foil-side of the box about a few inches above the other side of the box. You should see an outline of the moon as it crosses over the sun on the piece of paper.

The pizza box viewer is essentially a pinhole camera, which harnesses a property of light called diffraction to bend and magnify light. In this case, that's the sun as it eclipses.

Unlike certified protective glasses that are quickly selling out, a pinhole camera won't allow you to look directly at the eclipse, but it's good, last minute-alternative.

pinhole camera eclipse

Looking straight into the eclipse without protection can damage your eyes or even blind you. According to NASA, the only time it's OK to look at a solar eclipse is if you are in the path of totality — a specific area where the moon will completely obstruct the sun — for a minute or two.

The DIY hack is both an easy way to make an eclipse viewer and a clever strategy by Pizza Hut to sell more pizzas.