Safe Solar Eclipse Viewing

It is always dangerous to look directly at the sun because its intense light can harm your eyes. You have probably experienced catching a glimpse of the sun out of the corner of your eye, and your instinct was to close your eyes and turn away from the intense light that was causing you some discomfort. That is the wise thing to do because it protects your eyes from damage.

The dangerous nature of looking at the sun becomes important when there is something interesting going on with the sun that makes you want to look at it – like an eclipse! So it is important that you protect your eyes by viewing the solar eclipse (or the sun on any regular day) safely.

Below you will find advice on safe sun viewing, using either eclipse glasses or projection.

Solar Eclipse Glasses or Viewers

These glasses or handheld viewers have a solar-filter material that is housed in a cardboard or plastic frame. You wear or hold the solar-filter material over your eyes. In this way you can safely look directly at the sun because the filter reduces the intensity of the light that reaches your eyes to safe levels.

CAUTION: Eclipse glasses are NOT the same as sunglasses of the type that you might regularly wear on a sunny day. The lenses of eclipse glasses are made of a special solar filter material that blocks out almost all light.

Example of eclipse glasses

There are many retailers online that sell eclipse glasses, more so in the United States rather than Canada. The glasses come in a wide variety of colourful cardboard frames, so you can choose a style that you like. BEWARE of counterfeit eclipse glasses, which may claim to meet the standards for safe solar filters, but actually do not. Before you order your glasses, make sure that the glasses manufacturer or distributor is listed on the American Astronomical Society’s Suppliers of Safe Solar Filters & Viewers page.

Once you have your eclipse glasses, store them carefully to avoid damaging the lenses. Each time you plan to use your glasses to view the sun, inspect them for damage before looking at the sun.

Projection Method

If you don’t have access to eclipse glasses or viewers, you can still watch a solar eclipse by projecting it. In this method, you will pass the sun’s light through a small hole, or binoculars, and focus that light on a white surface. Then you can safely view the projected image, because the intensity of the sun’s light has been diminished during the projection process.

Below are a few ways to project an image of the sun:

  • Use two pieces of stiff white cardboard (paper plates will do) to make a simple pinhole projector;
  • Use a cereal/cookie box, paper, and aluminum foil to make a pinhole viewer. (This box viewer will provide a better image than just the simple projector above, because the image will be in a darker viewing area);
  • If you have binoculars, use them to project the Sun’s image on to white cardboard. If you have a tripod mount for your binoculars, that’s even better because you won’t have to hold them for the duration of your viewing. Do NOT look through the binoculars while they are pointed at the sun. Beware the heat that will be generated near the eyepieces. Give your binoculars breaks from being focussed on the sun every few minutes so that they don’t overheat. Do NOT leave this apparatus unattended!
People viewing a partial solar eclipse that has been projected through binoculars, in Charlottetown on August 21, 2017 (Photo: UPEI)

Photographing the Eclipse Safely

If you think you’d like to photograph the eclipse, read these tips on how to do it safely and still get good pictures. There is also a product available for purchase that will let you attach a solar filter to your smartphone (with Velcro) that comes with an app to help you photograph the sun or an eclipse.