Read our Privacy noticeAstronomers have shared photographs of glasses used to view eclipses almost one hundred years ago, ahead of the best solar eclipse in decades. The Royal Greenwich Observatory alone is said to have sold 15,000 pairs of eclipse glasses in the last month. They include images captured by 23-year-old physicist Arthur Schuster, who joined a Royal Society expedition to Thailand, then Siam, to view the eclipse. open image in gallery Photographic glass plates taken of a total solar eclipse in 1875 ( PA )Meanwhile, experts have warned that only special solar eclipse glasses that are ISO 12312-2 certified for the safest eye protection should be used to view Wednesday’s eclipse and that sunglasses were not sufficient. “Looking directly at the sun during a solar eclipse can cause damage to the retina, potentially damaging the cells responsible for sharp central vision.