Now, Specsavers has told The Argus that it made a conscious decision not to produce or supply eclipse glasses due to sustainability concerns. The company stressed that ordinary sunglasses are not safe for eclipse viewing and advised people only to use certified eclipse glasses meeting the ISO 12312-2 safety standard. Steve Ward, from the society, told The Argus that shortages of eclipse glasses in the run-up to an eclipse were not unusual. "Solar eclipse glasses are not toys and children should only use them under adult supervision." Mr Ward added that eclipse glasses typically have a shelf life of around 10 years, after which they should be replaced.