Safely Viewing the April Solar Eclipse: Tips on Using Eclipse Glasses and Identifying Key Features

Watching a total solar eclipse is an experience you’ll never forget, but if you don’t take the right precautions, it could end up for the wrong reasons. Looking directly at the sun can be dangerous, so read on to learn how to safely observe a solar eclipse and what you need to prepare in advance.

On April 8, 2024, a total solar eclipse will be visible to more than 42 million people across North America. The total path is only about 185 kilometers wide and touches Mexico, 13 U.S. states, and parts of Canada. Most people in North America will experience this phenomenon as a partial solar eclipse, rather than a total solar eclipse.

“For those outside the path of totality, the moon will never completely cover the sun,” he says. Jeff Todd At Prevent Blindness, a Chicago-based eye care advocacy group. No matter how you look at it, eye protection is essential.

“To avoid damaging your eyes, you should wear eclipse glasses throughout the eclipse,” says Todd. Otherwise, you risk burning your retina. This phenomenon, also known as “eclipse blindness,” can occur painlessly and can be permanent. It may take several days after seeing a solar eclipse before you realize something is wrong. Sunglasses do not provide sufficient protection. However, it is perfectly safe to wear eclipse glasses over your prescription glasses.

How to safely view a solar eclipse

The prize for those traveling the path of totality is seeing the sun’s corona with the naked eye. However, it is only visible for a short few minutes during totality. Otherwise, partial phases will be visible and must be observed through eclipse glasses. Todd says people on the path to totality should wear eclipse glasses at all times, except during totality, a brief period of darkness when the sun is completely hidden by the moon. “Only then can you take off your eclipse glasses,” he said.

It is important for those in the path of totality to use their naked eyes to view the Sun during a total solar eclipse. “You have to look without a protective filter, otherwise you won’t see anything,” he says. ralph chow At the University of Waterloo, Canada.

Just before totality ends, light from the Sun’s photosphere flows between the Moon’s peaks and valleys. Called Bailey beads, they appear for a few seconds and eventually become a flashing “diamond ring,” exposing enough of the sun’s photosphere for sunlight to return. “It gives us ample warning that it’s time to resume viewing partial solar eclipses with protective filters,” Chow said.

Which solar eclipse glasses should I buy?

It is important to wear eclipse glasses that meet the ISO 12312-2 international standard. ISO 12312-2 applies to products used for direct viewing of the sun. “Look for the ISO standard label and buy your glasses from a trusted source,” says Todd. “Get your glasses early in time for the eclipse.” Before you buy, make sure the company or brand is listed on the American Astronomical Society’s site. A vetted list of suppliers and resellers.

Do not use Eclipse glasses with binoculars or telescopes. If you want to use these instruments to observe a solar eclipse, you’ll need to attach a solar filter over the objective lens (the lens opposite the one you’re looking through). Never place solar filters or eclipse glasses between the telescope eye and the eyepiece or binocular eyecup.

Another way to safely view the eclipse is with a pinhole projector. This is a simple device that projects an image of the sun onto paper or cardboard through a small hole. An even easier method is to use a colander or a small hole in a spaghetti spoon. This projects a small crescent sun onto every surface.