Alright, let's dive into the world of eclipse glasses and the significance of the ISO 12312-2 certification!
What does ISO 12312-2 certification mean for eclipse glasses?
The ISO 12312-2 certification is an international safety standard specifically designed for filters used for direct viewing of the Sun. When you see eclipse glasses or handheld solar viewers labeled with ISO 12312-2 (sometimes written as ISO 12312-2:2015), it means that they have met the stringent requirements set by the International Organization for Standardization (ISO) to ensure the viewer's safety.
How is the testing performed?
To be certified as ISO 12312-2 compliant, the filters used in eclipse glasses or viewers must undergo rigorous testing in specialized labs. These labs are accredited to perform the necessary tests to verify compliance with the ISO 12312-2 safety specifications. The testing process involves using a spectrophotometer, a specialized and expensive piece of laboratory equipment. This device shines intense UV, visible, and infrared (IR) light through the filter and measures how much light gets through at each wavelength. Filters that pass the test not only reduce visible sunlight to safe and comfortable levels but also block almost all harmful solar UV and IR radiation.
Why is it crucial to use ISO certified eclipse glasses when viewing an eclipse?
Safety first! The Sun emits a tremendous amount of light and potentially harmful ultraviolet (UV) and infrared (IR) radiation. Looking directly at the Sun without proper protection can cause severe eye injury, and in some cases, even blindness. Regular sunglasses, no matter how dark, are not designed to protect your eyes from the intense light and radiation of the Sun.
Eclipse glasses that are ISO 12312-2 certified are designed exclusively for looking directly at the everyday Sun. They reduce sunlight to safe levels and block almost all of the Sun's harmful UV and IR radiation. These special-purpose solar filters are at least 1,000 times darker than ordinary sunglasses!
However, it's essential to be cautious. In the past, the market has seen counterfeit eclipse glasses that were labeled as ISO-compliant but had not been properly tested. This means that just seeing the ISO logo or a label claiming ISO 12312-2 compliance isn't enough. It's crucial to ensure that the glasses or viewers are genuinely safe and come from a reputable source.
In conclusion, when it comes to viewing a solar eclipse, it's always better to be safe than sorry. Using ISO 12312-2 certified eclipse glasses ensures that you can enjoy the beauty of an eclipse without risking your eyesight. So, the next time you're gearing up for an eclipse, make sure to grab your certified glasses and enjoy the celestial show safely!