what are eclipse glasses

Solar eclipse glasses are special eyewear designed for direct viewing of the Sun. They are required for safe viewing of solar events such as eclipses because standard sunglasses are unable to filter out eye-damaging radiation. Solar viewers are made with solar filters that conform to a worldwide safety standard known as ISO 12312-2. These filters reduce visible sunlight to safe and comfortable levels and block all but a tiny fraction of solar UV and IR radiation. According to the American Astronomical Society (AAS), products meeting the ISO 12312-2 standard avoid the risk of damage, and they have issued a list of reputable vendors of eclipse glasses. The organization warned against products claiming ISO certification, or even citing the exact standard number, but not tested by an accredited laboratory, or those bearing incomplete certification information. Counterfeit eclipse glasses have been a problem in the past, so it is important to buy from reputable sellers featured on the AAS list or from others that have been approved by the organization to ensure that they meet current safety standards. Regular sunglasses or homemade solar filters are not safe for watching an eclipse because they transmit sunlight at a rate that is thousands of times too high.