People in the U.S. will be treated to a spectacular show in the sky on April 8, 2024: a solar eclipse. A solar eclipse happens when the moon passes between the Earth and the sun, blocking the sun from view. The U.S. saw its last solar eclipse in 2017. Before that, the last time there was an eclipse in the mainland U.S. was 1979. According to NASA, we won’t see another until 2044.
In the Washington, D.C., metropolitan area, we can expect to see almost 90% coverage of the sun. The eclipse will be visible here from about 2 to 4:30 p.m., with maximum coverage around 3:20 p.m.
As you get ready to view the solar eclipse, remember that it is not safe to look directly at the sun—even when it is partially covered in an eclipse. Even a reduced amount of sunlight can permanently damage your vision. Consider these tips to stay sun safe while enjoying the eclipse.
1. Do not look at the sun with the naked eye.
On a normal day, looking directly at the sun is uncomfortable, causing you to blink and look away. As the moon blocks more of the sun’s light during a solar eclipse, your pupils become larger to let in more light. This disengages the normally protective pupillary response that keeps out harmful, unnecessary light rays, allowing the sun’s UV rays to enter your eyes.
The eye’s lens acts like a magnifying glass, focusing light onto the retina. The retina is a thin layer of cells at the back of the eyeball that is sensitive to light. It triggers nerve impulses to the brain, forming a visual image. When sunlight enters the eye, it can burn a hole in the retina, just like using a magnifying glass to burn holes in a piece of paper.
Eye damage caused by looking directly at the sun is called solar retinopathy. Retinas don’t have pain receptors, so you can permanently damage your vision without even feeling it. Once cells are dead, the damage can’t be undone. And it only takes a few seconds.
The degree of damage can vary. Symptoms of solar retinopathy can include:
- A blind spot in your central vision
- Blurred vision
- Difficulty discerning shape and detail
- Discomfort with bright light
To protect your eyes from solar retinopathy while still enjoying the eclipse, ensure you have proper eye protection.
2. Wear eclipse glasses that meet international standards.
Put away your sunglasses. They won’t protect your eyes when looking directly at the sun, even during an eclipse. Looking through multiple pairs of sunglasses won’t work either.
You have a couple of protective eyewear options. The first is No. 14 welder’s goggles, the only goggles dark enough for safely looking at the sun.
Your other option is eclipse glasses that contain special-purpose solar filters that meet international standard ISO 12312-2 for safe viewing. These glasses filter out most of the natural light but will allow you to safely see the eclipse.
Inspect your glasses before the big day, especially if you’ve had them around since the last eclipse in 2017. Check for scratches or other damage that could let light through. Make sure you can’t see anything through the glasses except the sun. If you can, they won’t protect you.
Be wary of shady businesses taking advantage of eclipse excitement. Check out the American Astronomical Society’s list of companies whose products have been laboratory-tested to meet safety standards.
As the eclipse gets closer, many retail stores will be sold out of safe eyewear. Shop early, or consider picking up free glasses from a source like a participating library.
3. Make a pinhole camera.
You can watch the eclipse safely without looking directly at the sun by making a pinhole camera.
NASA’s Jet Propulsion Laboratory recommends this easy process:
Materials
- 2 pieces of white card stock (white paper plates work)
- Aluminum foil
- Tape
- Pin or paper clip
Directions
- Cut a square out of the middle of one of the pieces of cardstock.
- Tape a piece of aluminum foil over the square.
- Poke a hole in the foil using the pin or paper clip.
- Place your second piece of cardstock on the ground.
- Stand with the sun behind you and hold the cardstock with the aluminum foil hole above your shoulder, allowing the sun to shine through the hole and onto the cardstock on the ground. The eclipse will be projected onto the cardstock on the ground.
4. Watch the eclipse on a monitor.
If you can’t get your hands on protective eyewear or don’t want to make a pinhole viewer, you can watch a broadcast of the eclipse on TV, a computer, or your smartphone. It won’t be the same thing as seeing it firsthand, but your eyes will stay safe.
The Smithsonian’s National Air and Space Museum will host a Solar Eclipse Festival on the National Mall from noon to 4 p.m. and will offer stations where you can view the eclipse through a safe solar telescope, among other activities.
If you can’t see the eclipse as it happens, NASA publishes breathtaking photos on its website, including the total eclipse, which will be visible in some parts of the U.S.
5. Use a solar filter on your camera, telescope, or binoculars.
A solar eclipse can make for a stunning photo, but it will require a few extra safety precautions. Just like your eyes need eclipse glasses, you’ll need to attach a solar filter to your camera, and smartphone.
Don’t look at the eclipse through an unfiltered camera, telescope, or binoculars, even if you’re wearing glasses. The concentrated solar rays could damage the glasses and injure your eyes.
Bonus eclipse safety tips.
While a solar eclipse poses the greatest danger to your eyes, here are a few other things to keep in mind:
- Prepare for a drop in temperature: In the path of totality, temperatures can drop 10 degrees or more. Even in D.C., where the moon will only partially cover the sun, we’ll still feel a chill. Grab a jacket or a blanket when you watch, just in case.
- Drive safely: If you want to see the eclipse, pull over. Don’t watch and drive. Even if you’re not watching the eclipse, expect other drivers to be doing so. Pay extra attention to the road and those around you.
- Wear sunscreen: Even though the sky will turn dark during the eclipse, the sun’s rays will still hit your skin. Don’t forget to apply some sunscreen.
By following these simple tips, you can stay safe and comfortable during this awe-inspiring event. Enjoy the show!
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