To safely watch a solar eclipse, you need either certified solar viewing glasses or an indirect method like a pinhole projector. Looking at the sun without proper protection, even during a partial eclipse, can cause permanent vision damage in seconds. The next major total solar eclipse crosses Greenland, Iceland, Portugal, and northern Spain on August 12, 2026.
Why Solar Eclipses Require Eye Protection
The sun emits ultraviolet and infrared radiation that your eyes can’t see but that penetrates directly to the retina, the light-sensitive tissue at the back of your eye. During an eclipse, the dimmed sky tricks your pupils into opening wider than they normally would in bright sunlight, letting even more of that radiation in. The concentrated energy causes photochemical and thermal damage to the cells responsible for your central vision. Retinal tissue temperatures can rise by 10°C or more, enough to destroy photoreceptor cells.
The resulting condition, solar retinopathy, typically affects both eyes and causes blurred central vision, blind spots, distorted images, light sensitivity, and headaches. In some cases, the damage is permanent and significantly limits everyday tasks like reading and driving. Regular sunglasses, even very dark ones, do not block enough radiation to make direct viewing safe.
Lunar eclipses, by contrast, are completely safe to watch with the naked eye because you’re looking at reflected sunlight, which is far too dim to harm your retina.
Certified Eclipse Glasses
The simplest way to watch a solar eclipse is with handheld solar viewers or eclipse glasses that meet the ISO 12312-2 international safety standard. This certification means the filters block 99.999% of sunlight. Look for the ISO number printed on the glasses themselves before you buy or use them. Inspect the filters for scratches, punctures, or separation from the frame before every use, and discard damaged pairs.
You need these glasses during every moment of a partial or annular eclipse, with no exceptions. During a total solar eclipse, there is one brief window when you can remove them: only after the moon has completely covered the sun’s bright face and the sky goes suddenly dark. As soon as any sliver of bright sunlight reappears, put them back on immediately.
Using Binoculars or Telescopes Safely
Looking through binoculars, a telescope, or a camera lens at the sun without a proper solar filter will cause severe eye injury instantly. The optics concentrate sunlight the same way a magnifying glass does. If you want to use any optical instrument, a certified solar filter must be attached to the front of the device, over the objective lens, so light is filtered before it enters the optics and gets magnified. Never place a filter behind the eyepiece or over a finder scope, where focused sunlight can crack or melt the filter material in seconds.
Standard eclipse glasses worn over your eyes do not protect you when looking through magnifying optics. The instrument gathers far more light than your unaided eye, overwhelming the filter’s capacity.
Building a Pinhole Projector
If you don’t have eclipse glasses, a pinhole projector lets you watch the eclipse indirectly and safely. You never look at the sun at all. Instead, you project an image of it onto a surface.
The simplest version requires two pieces of white cardstock. Poke a small, clean hole in one piece with a thumbtack. Hold it up so sunlight passes through the hole and falls onto the second piece, which acts as a screen. You’ll see a small, round image of the sun. As the moon crosses in front of it, the projected circle will show the same crescent or ring shape you’d see if you looked up.
A box version works even better. Take a long cardboard box (a cereal box works fine), cut a small square opening at one end, tape a piece of aluminum foil over it, and poke a tiny pinhole in the foil. Tape a piece of white paper inside the opposite end of the box as your screen. Look through a viewing hole cut in the side, and you’ll see a projected image of the eclipse. NASA recommends this approach as a safe, fun option for anyone without certified glasses.
You can also look for natural pinhole projectors around you. Gaps between tree leaves project dozens of tiny sun images onto the ground, each one showing the eclipse’s shape during the event.
Photographing the Eclipse With a Smartphone
Your phone’s camera sensor can be damaged by prolonged direct exposure to the sun, and pointing your phone at the sun also tempts you to look at the screen and then the sky. Use a certified solar filter over the camera lens for all partial phases.
Baader AstroSolar film, which carries ISO 12312-2 certification, is a popular and affordable option. It comes in sheets you can cut to size and hold or tape over your phone’s camera. Once the filter is in place, tap the screen to set focus, then adjust exposure downward until the sun’s disk looks sharp and defined rather than a bright glare. On iPhones, flick up on the camera screen and use the plus/minus exposure control to lock in a setting across multiple shots. On Android, switch to Pro mode and adjust exposure compensation manually.
Use a two-second self-timer to avoid shaking the phone when you press the shutter button. A small tripod with a smartphone holder gives you steadier results and frees your hands. If your phone supports RAW image capture, enable it to preserve more detail for editing later.
During totality (total eclipses only), you can remove the solar filter to photograph the sun’s corona. Switch to burst mode to catch the brief moment when the last bead of sunlight disappears and the corona appears. For video, set the phone in wide-angle mode, start recording a couple of minutes before totality, lean it against something stable or mount it on a tripod, and let it run through the entire event.
The August 12, 2026 Total Solar Eclipse
The next total solar eclipse occurs on August 12, 2026. The path of totality, the narrow strip where the moon completely blocks the sun, crosses the Arctic Ocean, Greenland, Iceland, the Atlantic Ocean, Portugal, and northern Spain. If you’re anywhere within this path, you’ll experience a few minutes of total darkness in the middle of the day and can briefly view the sun’s corona with the naked eye.
If you’re outside the path of totality but still in the broader region, you’ll see a partial eclipse. That’s still dramatic, but there is no safe moment to remove your solar filter at any point during a partial eclipse.
Planning for Clear Skies
Cloud cover is the biggest threat to your viewing experience, and you can’t control it. Start checking weather forecasts for your chosen location about a week out, and be prepared to travel if your area looks overcast. Coastal and mountainous regions can be especially unpredictable.
NASA’s free Helioviewer tool (eclipse.helioviewer.org) lets you view real-time images of the sun’s corona captured by the SOHO spacecraft, stationed a million miles from Earth. If clouds block your view on eclipse day, this tool provides eclipse-like imagery from space. A downloadable version called JHelioviewer adds 3D movie capability. These won’t replace the experience of watching in person, but they offer a solid backup and a way to study the sun’s outer atmosphere before and after the event.