Not every part of the island will have a clear sky. The National Geographic Institute has forecast the cloud cover area by area, and the news is good for most of the south and north. The clearest skies are expected around El Golfo and along the whole south-west coast, at Playa de Famara and the cliff above it, and in the northern villages of Guinate, Haría and Yé. The exception is a band of low cloud forecast over Tinajo, La Santa, Soo, Caleta de Caballo and Caleta de Famara, so if you are staying near there, it is worth heading for the south-west or the north to be sure of a view.
Staring at the sun without proper protection can cause permanent, irreversible damage to the retina, and it happens even when the sun is mostly covered. The only glasses safe to look through are ones certified to the correct standard, and the certification is printed on them. Look for the CE mark and a reference to the standard EN ISO 12312-2, which is the specification for filters made for looking straight at the sun. The manufacturer should be named on them, and the filter should be free of scratches, holes or bubbles, because a damaged pair is no longer safe even if it once was.
Sunglasses do not offer any sort of protection and avoid things like X-ray film, CDs, DVDs, 3D cinema glasses and anything homemade. Put your certified glasses on before you turn towards the sun, keep them on throughout, and keep children and older relatives from sneaking an unprotected glance, since the damage takes only seconds. Do not look through a camera, phone, binoculars or a telescope while wearing eclipse glasses either, as the magnified sun will burn straight through them without a proper solar filter fitted to the device.
Certified glasses have been selling out across the island, so if you cannot find a pair, do not fall back on anything unsafe. Instead, watch the eclipse indirectly by projecting the sun through a pinhole in a piece of card onto a flat surface, which shows it perfectly safely. There is also a free public viewing point on the maritime promenade at La Santa, above the steps, running from 5pm to 9pm with telescopes and approved glasses handed out by the Elder Museum, though bear in mind La Santa sits in the cloudier band, so it is the telescopes and glasses that make it worth a visit rather than a guaranteed clear sky.
