On August 12, a rare total solar eclipse will sweep across parts of Europe, drawing thousands of skywatchers from Reykjavík to Madrid. The Moon will pass directly between Earth and the Sun, casting a shadow that will be visible in Greenland, Iceland, Spain, and a small area of northeastern Portugal. Elsewhere on the continent, observers will see a partial eclipse.
In Spain, the eclipse will travel from west to east, crossing the mainland before moving over the Balearic Islands. It marks the first total solar eclipse visible from mainland Spain since 1905, and it is the first of three such events expected over the next few years. According to Philippe Escoubet, a space plasma scientist at the European Space Agency, these occurrences are rare on a local scale: “This kind of eclipse happens quite often on Earth, but at different places. However, it happens in a specific place only every 400 years. So if you have an eclipse passing by your village or your city, it will not come back [for] 400 years, so it's almost a lifetime event that you want to see.”
But witnessing this celestial spectacle comes with a serious caveat: looking directly at the Sun can cause irreversible damage to your eyes. Eye-health professionals across Europe are urging the public to take precautions.
Choose the right glasses
The safest way to view the eclipse is with special-purpose solar viewing glasses that meet the ISO 12312-2 international safety standard. However, Gabriëlle Janssen, president of the European Council of Optometry and Optics (ECOO), warns that the ISO number alone is not a guarantee of safety. “The ISO number printed on the glasses does not by itself guarantee that they have been properly tested,” she told European Pulse.
Janssen advises buying eclipse glasses from a reputable supplier and inspecting them for scratches, holes, or other damage before use. The glasses should be put on before you look toward the Sun, and removed only after you turn away. Children, she stresses, should be closely supervised.
If you do not have certified eclipse glasses, do not attempt to look at the Sun directly. Instead, follow the event through a livestream, such as the one provided by the European Southern Observatory (ESO). Ordinary sunglasses, even very dark ones, are not a safe substitute. “They do not provide sufficient protection against the intense visible, ultraviolet and infrared radiation from the Sun,” Janssen explains.
Beware of cameras, binoculars, and telescopes
Using cameras, binoculars, or telescopes without a specially designed solar filter is equally dangerous. “Wearing eclipse glasses while looking through these devices is not sufficient, because the concentrated sunlight can damage both the filter and the eyes,” Janssen says. Older folk methods, such as using CDs or photographic negatives, should also be avoided. “They don't block enough [light], and then some light is passing by. This can be very dangerous for your eyes,” Escoubet adds.
For those planning to photograph the eclipse, ensure your equipment is fitted with a proper solar filter, and never point an unfiltered lens at the Sun.
Why eye protection matters
The total phase of an eclipse lasts only a few minutes, but the damage from staring at the Sun can be permanent. The Sun's intense radiation can cause solar retinopathy, a photochemical injury to the retina—the thin layer of tissue at the back of the eye. The macula, which is responsible for sharp central vision, is especially vulnerable.
“The retina has no pain receptors. This means that the damage can occur without pain and without the person immediately realising that anything is wrong,” Janssen says. Symptoms often appear hours later and may include blurred or reduced central vision, a dark or blind spot in the center of the visual field, distorted vision (straight lines appearing bent), changes in color perception, and increased sensitivity to light.
Anyone who notices these symptoms after viewing the eclipse should avoid further exposure and seek prompt assessment from an optometrist, ophthalmologist, or other eye-care professional. While mild damage often improves over weeks or months, full recovery is not guaranteed. “Currently there is no proven treatment that can reverse solar retinal damage,” Janssen notes. “Prevention through correct eye protection is therefore essential.”
As Europe gears up for this rare event, authorities in several regions are also preparing for its practical impacts. In Spain, the government has offered free power to households that reduce consumption during the eclipse, while the Balearic Islands have tightened security on land, sea, and air to manage the expected influx of visitors. For those who miss this one, Spain is already preparing for a rare trio of eclipses starting in 2026.
