Anyone watching must use specialist solar eclipse glasses or a handheld solar viewer which meets the international ISO 12312-2:2015 safety standard. Stock is selling quickly ahead of the eclipse, but eclipse glasses were reported to be available at Robert Dyas in Wokingham on Tuesday. Royal Observatory Greenwich and National Maritime Museum: Limited eclipse glasses are available from the on-site shops. First Light Optics: The astronomy supplier is selling certified Baader eclipse glasses online, though its packs have a minimum order quantity. Only use glasses or handheld viewers marked ISO 12312-2:2015 (or EN ISO 12312-2:2015) and bought from a reputable supplier.