To safely view a solar eclipse, it is important to use glasses that meet the ISO 12312-2 international safety standard. These glasses are specifically designed to block out harmful radiation and reduce visible sunlight to safe and comfortable levels. Ordinary sunglasses, neutral density or polarizing filters, and smoked glass are not safe for viewing a solar eclipse.
When purchasing eclipse glasses, it is important to check that they are ISO-compliant and have been properly tested and shown to be safe. Reputable vendors and manufacturers of eclipse glasses include Lunt Solar Systems, American Paper Optics, Rainbow Symphony, and Celestron EclipSmart.
It is also important to note that eclipse glasses and sunglasses are made of different materials and should not be used interchangeably. Sunglasses do not provide adequate protection for viewing a solar eclipse and should never be used to look directly at the sun.
