How to Make Solar Eclipse Glasses

Last Updated: 28 February, 2019 by Alexander Thomas

How to Make Solar Eclipse Glasses

A total solar eclipse can be a rare and spectacular sight. Although the phenomenon happens quite often around the world, it always takes place in different locations, which means that people in a specific state or country only get to see a few total solar eclipses in their lifetimes (unless, of course, they choose to travel specifically for this purpose).

When the next total solar eclipse visible in the United States on April 8, 2024, you’ll want to be prepared for the event, especially if you live in Texas, Oklahoma, Arkansas, or other states in the path of totality. Protective eyewear is a must for anyone observing the sun during an eclipse, but retailers usually run out of glasses fast during such rare events.

If you find yourself in such a situation or if you simply want to have some nerdy fun, you can learn how to make solar eclipse glasses and other gadgets from a variety of materials. Read on for everything you need to know.

What Happens During the Solar Eclipse?

A solar eclipse occurs when the Moon comes between the Sun and the Earth, casting its shadow in various regions across the globe. Any such phenomenon is named by its darkest phase, which means that when the Moon covers the Sun entirely for viewers at one location on Earth, the event is referred to as a total solar eclipse (or totality), even though viewers from other regions see only a partial eclipse or no event at all.

During a total solar eclipse, the Moon gradually becomes visible across the disc of the Sun. At first, the Sun looks as if it was bitten from the side, whereas by the time the total eclipse proper occurs, the Sun’s disc is entirely covered by the Moon.

The Maximum Eclipse (Totality)

At this point, viewers in the path of totality can observe the diamond ring effect (where only the solar corona and a single “jewel” of light are visible), as well as Bailey’s beads (minuscule blobs of light on the edge of the Moon). During the maximum eclipse, the sky is dark and temperatures can drop. After a few minutes (at most), the Moon begins to move away from the Sun and eventually stops overlapping the Sun’s disk.

Why Do You Need Solar Eclipse Glasses?

Observing a total solar eclipse can be a unique, once-in-a-lifetime event, but in order to safely enjoy the beautiful display, you must wear special protective eyewear. At the very least, you should wear a pair of homemade eclipse glasses. Why is this the case though?

You probably already know that it’s not safe to stare directly into the Sun even when an eclipse is not taking place. The Sun simply puts out more power than the human eye can safely handle, which means that prolonged exposure can lead to damage of the retina. In addition, you do not have any nerves on your retina that would otherwise warn you of the peril. In short, you can damage your eyesight without even knowing it until later on.

The risk is particularly high during a solar eclipse.

During the Eclipse…

The most spectacular moments of the solar eclipse are spent in the dark, which means that your pupil is dilated to allow you to see things better. When the Sun reappears from behind the Moon, it does so suddenly, before you have the chance to avert your gaze. Furthermore, the Sun immediately floods the area with extremely bright and potentially harmful light.

Because you are staring straight at the Sun and because your eye is accommodated with the dark, you risk permanent damage of the retina. That is why you absolutely must wear solar eclipse glasses, DIY eclipse glasses (not sunglasses!), or, alternatively, observe the event through an eclipse viewer.

But what if you forgot to buy special eyewear or your glasses were damaged before the eclipse? Here are a few things you can do.

How to Turn Your Room into an Eclipse Viewer

Homemade eclipse glasses are not the only solution to observe a solar eclipse without special eyewear. In fact, if you don’t have the materials you need to learn how to make solar eclipse glasses, you can turn your room into an eclipse viewer instead.

What You Need

To create an eclipse viewer in your own room, you’ll need a nail and some form of cover for your windows. You can use black trash bags or any other material that will obscure the windows to your room.

It’s essential, however, that your room is positioned in such a way as to make the viewing of the eclipse possible. This means that your windows should not be obscured by trees or other buildings and that the room should face towards the sun at the time of the eclipse.

How to Prep Your Room

Well before the eclipse occurs, cover the windows to your room with opaque material. Close the door(s) and make sure that no other light source is available inside the room. Then, use the nail to puncture a very small pinhole in one of the covers.

If you’ve prepped the room correctly, what you will observe as soon as you puncture the material is the “camera obscura” effect. Due to this phenomenon, you’ll see an upside-down projection of the world outside of the room on your walls.

During the eclipse, all you have to do is uncover the hole in the window and face away from it while looking at the opposite wall. Provided that your window has a view of the eclipse, you’ll see a projection of the entire movement of the Moon across the Sun on the wall vis-à-vis of the window.

Remember that it is dangerous to look straight at the sun during the eclipse. Do not look outside through the pinhole, but rather observe the eclipse by facing away from the window and towards the opposite wall.

How to Make a Portable Eclipse Viewer

Unfortunately, it’s very likely that your room is not suitable to become an eclipse viewer because it does not have a view of the Sun at an appropriate angle or because the sight is blocked by trees and/or other buildings. If this is, indeed, the case, consider building a DIY, cereal box eclipse viewer.

What You Need

You only need a few basic supplies to create your own portable cereal box eclipse viewer. These include an empty cereal box (or any carton box that can be sealed shut), a white piece of paper, scissors, tin foil, some tape to glue everything together, and a nail or some other sharp object you will use to pierce a small hole.

If you don’t have a carton box lying around, you can also make your own box by taping together six sides into a rectangular shape. Just make sure that the box you use can be taped shut to ensure the “camera obscura” effect.

How to Make a Pinhole Eclipse Viewer

First, make sure that the cereal box is completely empty. Then, place it standing on top of the white piece of paper. Use a pencil to trace the bottom of the box on the piece of paper, then remove the box.

Cut out the shape you’ve just traced on the white piece of paper and place it inside the cereal box, on the bottom. Tape it there. Next, shut the top of the box and use the scissors to cut two square holes into it, on the left and the right sides.

Cut a piece of tin foil large enough to cover one of these holes at the top of your cereal box. Tape the piece of tin foil to the box in such a way as to cover one of the holes. Finally, take the nail or other sharp object and pierce a very small hole in the tin foil.

All done! To observe a total solar eclipse using the cereal box eclipse viewer, position yourself so that you are facing away from the Sun, with the light shining over your shoulder. Hold the box in front of yourself and look downwards into it through the hole that remains uncovered.

What you will see is a projection of the Moon moving over the Sun on the bottom of the cereal box, which should be covered in white paper. Remember that the portable eclipse viewer works only if you face away from the Sun. Do not attempt to look at the Sun during the eclipse.

How to Make an Eclipse Viewer Using Binoculars

A cool variation of the portable cereal box eclipse viewer uses binoculars (no, not to look at the Sun directly!). To employ this method during an eclipse, you need only a carton board and a pair of binoculars.

Position yourself facing away from the Sun, with light shining over your shoulder. Hold the piece of carton in front of yourself and slightly lower than your chest. Then, position the binoculars with the lens pointed upwards, towards the Sun, and the eyepiece downwards, towards the carton board. Do not attempt to look through the binoculars directly at the Sun. The lens will focus the sunlight and potentially cause irreparable damage to your sight.

Instead, continue to face away from the Sun and look at the carton board. On it, you will see a projection of the total solar eclipse as rendered by the binoculars.

How to Make Solar Eclipse Glasses

If a solar eclipse viewer is not to your liking, then you might want to learn how to make solar eclipse glasses to prepare for a totality. The advantage of these glasses is that while you wear them you can look directly at the Sun instead of observing a projection of it on a different surface. The one disadvantage is that homemade eclipse glasses require solar filter, which you will have to buy from an authorized vendor.

What You Need

To whip up a pair of DIY eclipse glasses, you’ll need a large piece of carton or poster board, a template of the glasses you want to wear, a roll of tape, scissors, and a pen. Most importantly, you’ll need a decent sized solar filter.

For those looking to learn how to make solar eclipse glasses in the United States and elsewhere in the world, there are a wide variety of solar filters available for purchase. Remember, however, that only some of them were approved by NASA. In other words, only some solar filter manufacturers are guaranteed to sell filters that are actually safe to use during an eclipse. These will be referred to as “ISO certified”. To avoid any possible damage to your eyesight during the big event, stick only to approved brands when you purchase a solar filter.

How to Make Eclipse Glasses

Once you have all the materials together, it’s time to make your own eclipse glasses. If you’re making your own frame, then place your template on top of the carton and trace the appropriate shapes (or simply draw them yourself). Next, cut out the shapes, which should include a frame with cutouts for the eyes and nose and two handles to help place the glasses on your ears. Tape all the pieces together correctly to finish the frame.

Alternatively, you can use an old pair of 3D glasses. Just remove the lenses and you’re good to go. The next step is to prepare the solar lenses. To do so, measure the size of the cutouts in your frame and cut the solar film with a generous margin for taping. Do not scratch or puncture the film as you prepare it, however, because this will ultimately reduce its effectiveness in protecting your eyes during the eclipse.

At this point, you’ve almost learned how to make solar eclipse glasses. Secure the solar film in place so that it covers the eye holes in your frame. Done – your very own homemade eclipse glasses are ready for testing!

How to Test Your DIY Eclipse Glasses

When it comes to such risks as permanent eye damage, it’s better to be safe than sorry. To make sure your homemade eclipse glasses will actually protect your eyes during an eclipse, take a friend with you in a completely dark room and ask them to point a bright flashlight in your direction while you wear the glasses.

You will see some light, but if the DIY eclipse glasses are safe then the light will be visible only in a yellow or orange hue. If, on the other hand, you see any bright light without a hue, then the glasses have a leak and are not safe to use during the eclipse. Good thing you checked before the actual event!

Simply use a new piece of solar film and go through the process once again. Don’t forget to test the new DIY eclipse glasses as many times as it takes to get a safety pass.

Can You Still See the Eclipse without Homemade Eclipse Glasses?

If you were not able to learn how to make solar eclipse glasses on time and you also don’t have a portable cereal box eclipse viewer, don’t worry. You can still experience the totality so long as you remember to never attempt to look directly at the Sun without protective eyewear.

When you have no other options, you can actually use your hands to achieve a projection of the eclipse. While facing away from the Sun, hold your hands one on top of the other with spread fingers so that you create a lace. With the Sun shining over your shoulder, let the light pass through your fingers and onto the ground. During the eclipse, you’ll see the Moon crescent projected on the ground, through your hands.

Even if you don’t have homemade eclipse glasses, you can still achieve a similar effect using any opaque object with small holes in it – even some crackers. Never attempt to look through the holes directly at the Sun, however. Instead, look away from the Sun and point the pierced object towards the ground to witness the Moon crescent projected there.

Homemade Eclipse Glasses: Safety Precautions

It can be fun to learn how to make eclipse glasses for a big solar event, but the most important thing is to keep yourself and your loved ones safe. If you buy pre-made glasses, make sure that they are ISO certified and approved by NASA. The same applies when you buy solar filter for DIY eclipse glasses.

Finally, remember that while it is never safe to stare directly at the Sun, this is particularly dangerous during a total solar eclipse. Whatever option you choose to bring with you during the eclipse, follow instructions to the letter and advise those around you to do the same.

How to Make Solar Eclipse Glasses: Summary

Following the eclipse in 2017, the next totality visible in the United States will occur on April 8, 2024. There’s still plenty of time to stock up on solar eclipse glasses, but if you somehow find yourself in need of protective eyewear prior to the big event, you’ll now know how to make solar eclipse glasses from scratch.

In addition, DIY eclipse glasses are not the only option to safely observe a total solar eclipse. For those with an inclination towards nerdy exploits, creating a portable “camera obscura” or eclipse viewer can be a fun and memorable experience. Once you have some kind of protective gear at hand, you’re ready to enjoy the spectacular sights.