Medical authorities in Spain and Portugal are urging caution ahead of the total solar eclipse on Aug. 12, warning that even brief exposure to unprotected sunlight can cause permanent retinal injury. Ophthalmologist Santiago Abengoechea of the Barraquer Ophthalmology Centre cautioned that retinal cells do not regenerate and such damage has no treatment. After a similar event in 1999, dozens of patients were treated for solar retinopathy.
Children are considered especially vulnerable due to greater lens transparency. The Balearic Islands health department advised that children under six should not watch the eclipse directly and said lesions can appear up to 48 hours later. Regional authorities have seized or destroyed 48 pairs of non-certified glasses and are deploying 160 additional health workers around the event.
Only ISO 12312-2 certified eyewear provides adequate protection, experts say. Astrophysicist Pedro Machado noted that certified glasses must block all but one-thousandth of solar light, adding that in Portugal the total eclipse will be visible only from the villages of Rio de Onor and Guadramil.