How to safely view the solar eclipse using household materials

With the solar eclipse just two weeks away, it’s time to think about how to safely view the celestial show.

For those who aren’t keen on buying solar eclipse glasses, Dr. Ilana MacDonald of University of Toronto’s Dunlap Institute for Astronomy and Astrophysics has an inventory of ways to protect your eyes with household materials.

On April 8, the moon will pass between the sun and the earth. When the moon aligns directly with the sun, it will completely shadow it for several minutes. A partial eclipse will take place just before 2 p.m. in southwestern Ontario, followed by a total eclipse at 3:12 p.m.

“Staring directly at the sun for more than a minute can cause permanent damage to the retina. That means that you'll actually have the back of your eye burned,” MacDonald said.

“And you'll be partially blind in part of your eye.”

One of the ways to keep your vision intact is with a pinhole viewer.

Take a piece of cardstock or index card and punch a hole through it, MacDonald advises. With the pinhole, you can project an image of the sun onto a surface, saving your eyes from looking directly at the luminous rays.

MacDonald recommends punching the hole with a shape that’s not a sphere to clearly see the circle of the sun shine through it.

“You can see that circle turning gradually into a crescent as the moon goes in front of the sun. So in that way, you can safely view the eclipse by projecting its image instead of looking directly at it. We call that an indirect viewing method,” MacDonald said.

To get fancy with it, you can make a shoebox pinhole camera by cutting a hole on one side of a box, putting a piece of aluminum foil over it and then pricking a very small hole in the foil, she said.

Put it into action by going outside, standing with the sun behind you and letting it shine through the pinhole, projecting the sun onto the other side of the shoebox.

For those less crafty, she said any household object with holes in it will work.

“If you have a colander, or a cheese grater with holes in it or things like that, you can actually project the image of the sun onto a surface using just holes from everyday objects,” she said.

If you are in the path of totality, it's actually safe to view the sun without eclipse glasses, MacDonald noted, but only during totality, the one to three minutes when the moon is completely covering the sun's surface.

The Dunlap Institute is running dozens of free workshops at the Toronto Public Library with a focus on safely viewing the total solar eclipse.