The safest way to watch a solar eclipse is with certified solar viewing glasses that meet the ISO 12312-2 standard, which block all but a tiny fraction of the sun’s light. If you don’t have glasses, a simple pinhole projector made from household materials works just as well. The method you choose depends on whether you’re watching a partial eclipse or a total one, since the rules change briefly during totality.
Solar Eclipse Glasses
Dedicated eclipse glasses are the simplest option. Look for glasses labeled with the ISO 12312-2:2015 certification, which sets strict limits on how much ultraviolet, visible, and infrared light can pass through. A compliant filter transmits roughly the same amount of light as a shade 12 to shade 15 welding filter, meaning the sun appears as a bright, well-defined disk against a dark background. Through proper eclipse glasses, you shouldn’t be able to see anything else, not your hand in front of your face, not the ground, nothing but the sun itself.
Before using a pair, hold them up and look around your house. If you can see lamps, windows, or any ambient light, they’re too weak. Legitimate solar glasses make ordinary indoor lighting completely invisible. Also inspect the filters for scratches, punctures, or peeling. Even a small defect lets concentrated sunlight through to your retina.
Using a Welding Helmet Instead
If you have access to a welding helmet, shade 14 is the recommended darkness level for solar viewing. Shades 12 and 13 offer some protection but let more light through than ideal. Even with a shade 14 filter, avoid staring continuously for long stretches. A welding helmet has the advantage of being sturdier and easier to hold steady than cardboard eclipse glasses, which makes it a good choice if you’re watching with kids who might fidget with flimsy frames.
Build a Pinhole Projector
If you don’t have glasses or a welding helmet, a pinhole projector lets you watch the eclipse indirectly. You never look at the sun at all. Instead, you project a small image of it onto a flat surface and watch the moon’s shadow creep across that image in real time.
You need two pieces of white card stock, a small square of aluminum foil, tape, and something sharp like a pin or paper clip. Cut a one- to two-inch square hole in the center of one piece of card stock, then tape aluminum foil over that hole. Poke a single small hole in the foil with your pin. Set the second piece of card stock on the ground, hold the foil piece above it with the foil side facing up, and stand so the sun is behind you. A tiny image of the sun will appear on the bottom card. The farther apart you hold the two cards, the larger the projected image. For a sharper picture, place the bottom card in a shaded area while keeping the top card in direct sunlight.
Colanders, crackers, even the gaps between interlaced fingers all work on the same principle. During a partial eclipse, you’ll notice that every dappled shadow under a leafy tree turns into dozens of tiny crescents on the ground.
The Exception: Viewing Totality
During a total solar eclipse, there is one brief window when you can look at the sun with your bare eyes. Once the moon completely covers the sun’s bright face and you enter totality, it’s safe to remove your glasses. You’ll know the moment has arrived when you can no longer see any part of the sun through your eclipse glasses or solar viewer. The sky darkens dramatically, stars and planets may appear, and the sun’s outer atmosphere (the corona) glows as a pearly white halo around the moon’s silhouette. This is the only time during any eclipse when unprotected viewing is safe.
Totality lasts anywhere from a few seconds to about seven and a half minutes depending on the eclipse and your location. The instant you see even a sliver of bright sunlight reappear at the moon’s edge, put your glasses back on immediately. That first flash of returning sunlight is just as dangerous as staring at the uneclipsed sun.
If you’re watching a partial or annular eclipse, there is no totality phase. The sun is never fully covered, so certified eye protection stays on the entire time.
What Happens If You Look Without Protection
Staring at the sun without proper filters, even for a few seconds, can cause solar retinopathy. The focused light essentially burns the cells at the center of your retina. Symptoms typically show up within hours to one or two days and include blurred vision, a blind spot near the center of your visual field, distorted vision where straight lines appear curved, colors looking different than normal, and objects appearing smaller than they should. Some people recover fully over weeks or months, but in severe cases the damage is permanent. The danger is that looking at the sun during an eclipse doesn’t hurt in the moment, so there’s no pain signal telling you to look away.
What You’ll Experience During Totality
A total eclipse is more than a visual event. As the moon’s shadow sweeps toward you, the temperature drops noticeably, typically by several degrees within minutes. The light takes on an eerie, metallic quality unlike anything you see at sunset. Shadows on the ground sharpen, and just before totality you may notice thin, rippling bands of light (called shadow bands) racing across flat surfaces.
Animals react as though night has suddenly fallen. During documented observations at zoos, gorillas walked toward their indoor enclosures in their normal evening hierarchy. Baboons huddled together and became visibly agitated, running in groups around their enclosure. Giraffes stopped eating, clustered near their barn entrance, and paced anxiously. Lorikeets flew toward their nest boxes. Even insects shift behavior, with moths becoming active as if dusk had arrived. If you’re in a rural area, listen for crickets starting up and birdsong going quiet.
Upcoming Total Solar Eclipses
The next total solar eclipse falls on August 12, 2026, with the path of totality crossing Greenland, Iceland, and Spain (plus a small area of Portugal). A partial eclipse will be visible across much of Europe, Africa, and North America.
The following year, on August 2, 2027, totality will sweep across southern Spain, Morocco, Algeria, Tunisia, Libya, Egypt, Saudi Arabia, and Yemen. A partial eclipse will reach most of Europe, much of Africa, the Middle East, Southeast Asia, and eastern Canada. Both events are worth planning travel around if you’ve never experienced totality firsthand, since a partial eclipse, no matter how deep, doesn’t come close to replicating what happens when the sun disappears completely.