Published on
05/08/2026 - 5:58 GMT+2
Make a note of this number for the eclipse that will cross the Iberian Peninsula on 12 August. With that date in mind, the ISO number (International Organization for Standardization) of the special glasses that must be used to view this unique event of the century safely should be easy to remember: 12312-2015.
Without them, ultraviolet radiation will damage the eye’s photoreceptors (cones and rods), while infrared energy will have a direct thermal effect on the retina, causing solar retinopathy. The symptoms of this condition, which may take some time to appear, can include blurred vision, spots or scotomas at the point of greatest visual acuity, metamorphopsia (distorted perception of shapes) and reduced tolerance to light, or photophobia, which can trigger headaches.
The total phase of the eclipse will not exceed one minute and 48 seconds anywhere along its path across Spain, and the closer you are to the line of totality, the longer you will be able to enjoy the spectacle. Only during that brief moment will lucky observers be able to take off their certified glasses.
