The total solar eclipse on August 12 will be visible across the Peninsula, but ophthalmologists warn that watching it without protection can cause solar retinopathy, an irreversible injury that does not hurt or become apparent immediately.
On August 12, Spain will witness a total solar eclipse, the first of three that make up the so-called 'triad of eclipses' visible from the country until 2028. Millions of people are preparing to look up at the sky, but visual health experts issue a clear warning: looking directly at the Sun without proper protection can cause permanent damage to the retina, even if no discomfort is felt at the time.
Dr. Francisco J. Muñoz, an ophthalmologist at the Hospital Clínico de Barcelona, explains that concentrated solar radiation burns the cells of the macula, the central area of the retina responsible for sharp vision. “The patient feels nothing during the observation. It doesn’t hurt, it doesn’t look strange. The damage appears hours or days later, when it’s already too late,” the specialist points out. This injury, known as solar retinopathy, can leave a permanent dark spot in the central visual field and even cause significant loss of visual acuity.
From the College of Opticians-Optometrists of Catalonia, they remind us that conventional sunglasses, even polarized ones, are not suitable for protection during an eclipse. Neither are homemade filters like X-rays, CDs, tinted glass, or plastic films. The only safe protection is certified glasses with ISO 12312-2 filters, which block 99.999% of sunlight. In Barcelona, several opticians have already started receiving orders for these viewers due to the high anticipated demand.
The eclipse on August 12 will be total in a band crossing the Peninsula from west to east, passing through provinces such as A Coruña, León, Burgos, Zaragoza, Lleida, and Girona. In the Barcelona area, the phenomenon will be seen partially, with an 85% darkening of the solar disc. The peak in the Catalan capital will occur at 12:30, with a total duration of the phenomenon of about two and a half hours.
The Spanish Society of Ophthalmology (SEO) has launched an informative campaign on social media and in the media to raise awareness among the population. Its president, Dr. José María Rodríguez, insists that “an eclipse is a fascinating spectacle, but a second of exposure without protection can ruin vision forever.” The SEO recommends purchasing glasses in advance from trusted establishments and verifying that they bear the CE marking and the ISO standard.
For those without suitable filters, the safe alternative is indirect observation: projecting the image of the Sun onto a white surface through a hole made in cardboard, or using a telescope or binoculars with a specific solar filter placed on the objective (never on the eyepiece). It will also be broadcast live on channels such as the YouTube channel of the Institute of Astrophysics of the Canary Islands.
In the metropolitan area of Barcelona, various civic centres and libraries have organised collective observation sessions with certified material. The Barcelona City Council, through the Institute of Culture, has announced observation points in parks like Ciutadella, where telescopes with solar filters will be set up and certified glasses will be distributed for free until supplies last.
The total eclipse of August 2026 is the first visible from Spain in 117 years, and the second of the triad: it will be followed by an annular eclipse in 2027 and another total in 2028. The anticipation is high, but specialists remind us that eye prevention must be a priority. “There is no treatment for solar retinopathy; prevention is the only cure,” concludes Dr. Muñoz.
Those interested can consult the website of the Spanish Society of Ophthalmology to find authorized points of sale for solar filters and updated recommendations. Additionally, the Institut d'Estudis Espacials de Catalunya has set up a citizen information phone line to resolve questions about safe observation of the eclipse.
You may also like
