Governments and media may warn that people should stay in their houses to avoid the dangers of the eclipse. In many local communities, habitants, especially children are advised not to go outside during the solar eclipse and watch the eclipse on television. In fact, it’s never safe to look at a partial or annular solar eclipse or the partial phases of a total solar eclipse, without using special solar filters. B. Ralph Chou (known as leading expert on protecting solar filters) explains that the only time to observe the Sun safely with the naked eye is during totality, when the Moon covers the Sun’s disk completely. Even when 99% of the Sun’s face is obscured during the partial phases of a solar eclipse, the remaining Sunlight is still intense enough to cause a retinal injury. Viewing the Sun through binoculars, a telescope, or other optical device without proper protective filters can result in immediate retinal injury because of the high irradiance level in the magnified image. Chou describes that any filters used to observe the partial or annular phases of a solar eclipse, should meet the transmittance requirements of ISO 12312-2 and eclipse glasses or viewers should not be used unless they comply with the requirements of ISO 12312-2.
On the other hand, observers should never look at the Sun through a camera, a telescope, binoculars, or any other optical device while using eclipse glasses or viewers. For more information about standard filters for camera lenses, binoculars & telescopes read Chou’s paper here.
Chou features the following items as the unsafe materials that should never be used for solar viewing:
•“Black” developed color film
•Exposed film negatives
•Sunglasses (single or multiple pairs)
•Photographic neutral-density filters
•Food wrappers (e.g., chips, Pop Tarts)
•CDs or DVDs
•Gardening films or similar pro
It’s very important to be aware that, the naked-eyes observation during the totality – when the Sun is completely covered by the Moon – is absolutely safe. Experiencing a total solar eclipse is one of the most spectacular moments in your life time, so you should not miss this rare opportunity if you are living within or not far away from the path of totality. It’s often very difficult and complicated for many people to chase the upcoming totalities of the Sun as it is often necessary to travel to remote locations to see a total solar eclipse.”
Jay M. Pasachoff, the chair of International Astronomy Union Working Group on Solar Eclipses argues that in the days before a solar eclipse, media often covers, warning about the dangers of looking at the eclipse. Unfortunately, despite the good fact behind these messages, they often have misinformation, and may be designed to scare people from observing the eclipse at all. This tactic may backfire, however, particularly when the messages are intended for students. A school student who heeds warnings from teachers or other authorities not to see the eclipse to avoid injuries, and later learns that other students have observed it safely, may feel cheated out of the experience.
Our eclipse glasses meet the requirements of ISO 12312-2 and ensure safe observation during the eclipse. The eclipse glasses will be available soon on eclipse262728.com before and during the eclipse years 2026, 2027 and 2028 in Spain.