How To Safely Make DIY Solar Eclipse Viewers At Home Ahead Of The August 12, 2026 Total Eclipse Event

With a total solar eclipse set to sweep across parts of the Arctic, Greenland, Iceland and Spain on August 12, interest in do-it-yourself eclipse viewing tools has surged — but safety experts and space agencies are cautioning that not every homemade option is safe for the eyes.

According to NASA and the National Solar Observatory, looking directly at the sun without proper protection can cause permanent eye damage, and that risk applies during a solar eclipse just as it does on any ordinary day, except during the brief window of total darkness known as totality. Outside of that narrow period, any glimpse of the sun's bright surface — even a thin sliver during a partial eclipse — can harm the retina, since the eye lacks pain receptors that would otherwise warn of the damage occurring in real time.

The August 12 eclipse will be total along a path crossing a remote stretch of northern Russia, Greenland, Iceland, northern Spain and a small corner of Portugal. Much of Europe, North America and northwestern Africa will see only a partial eclipse, meaning the moon will cover just a portion of the sun's disk rather than blocking it entirely. For viewers along the path of totality, NASA says it is safe to remove eye protection and look directly at the sun only during the short period when the moon fully covers it — and protection must go back on the instant any sliver of sunlight reappears.

For those hoping to build their own viewing equipment rather than buy certified glasses, safety officials say there are really only two legitimate do-it-yourself paths, and they are not the same thing.

The first, and by far the safest option for anyone without access to certified equipment, is an indirect method that does not involve looking at the sun at all: a pinhole projector. The concept is simple. A small hole poked into a piece of cardboard or an index card, held so sunlight passes through it and lands on a second surface such as another card, a wall or the ground, will project a small image of the sun's crescent shape during the partial phases of the eclipse. Because the viewer never looks directly at the sun, and instead observes its projected image, the method carries essentially no risk to eyesight and requires no special materials beyond basic household items.

The second path — building an actual pair of wearable eclipse glasses — is more involved and requires sourcing the correct material rather than improvising with household substitutes. According to the National Solar Observatory, homemade filters and ordinary sunglasses, even very dark ones, are not safe for looking at the sun under any circumstances, regardless of how many layers are stacked together. The only safe way to look directly at the sun's bright surface is through solar filter material specifically manufactured for that purpose and certified to the ISO 12312-2 international safety standard. That standard limits the amount of visible, ultraviolet and infrared light that reaches the eye to levels considered safe for direct solar viewing.

Genuine do-it-yourself eclipse glasses can be assembled at home, but only by purchasing pre-certified ISO 12312-2 solar filter sheets from a reputable supplier and mounting them into a simple cardboard or paper frame, rather than attempting to fashion the filtering material itself. The American Astronomical Society, the leading professional organization for astronomers in North America, maintains a list of verified, safe suppliers of solar filter material and eclipse glasses, and safety experts recommend checking any product against that list before use, particularly given a history of counterfeit eclipse glasses circulating around past eclipse events that failed to provide adequate protection despite carrying misleading safety labels.

For observers who already own welding equipment, the American Astronomical Society has said that welding filters with a shade rating of 12 or higher can also provide safe direct viewing, with shade 13 or 14 generally considered closest in darkness to standard eclipse glasses. Ordinary sunglasses, smoked glass, exposed photographic film, polarizing filters and stacked layers of dark plastic are all explicitly not considered safe substitutes, regardless of how dim the sun appears through them.

Anyone planning to photograph the eclipse or view it through binoculars, a telescope or a camera lens faces an additional layer of risk. NASA and other experts warn that a solar filter must be attached to the front of any such optical device, not simply held up to the eyepiece, since the lens will concentrate sunlight to a degree that can damage both the equipment and the eyes almost instantly. Wearing eclipse glasses while looking through unfiltered optics is not a safe workaround, experts say, since the concentrated light passing through the lens can burn through the glasses' filter material.

Timing will also matter for viewers hoping to catch the moment of totality. According to eclipse path data, totality is set to begin over Iceland at 1:45 p.m. Eastern time and reach Spain by 2:28 p.m. Eastern time on August 12. NASA has said it will provide live coverage of the eclipse beginning at 1:15 p.m. Eastern time, including footage from telescopes positioned along the path of totality and from a high-altitude research aircraft tracking the moon's shadow, for viewers outside the path who want to watch the event unfold in real time.

With demand for certified eclipse glasses expected to rise as the date approaches, safety officials are urging anyone planning to view the event directly to secure verified protective equipment well in advance, rather than relying on last-minute homemade alternatives that may not meet the safety standards needed to protect their eyesight.