The solar eclipse is set to begin just two weeks from Monday. If you are planning to watch the solar eclipse on August 21, there are some things you need to know to be prepared.
First, looking directly at the sun -- even during a partial eclipse -- can easily damage your eyes. The only time it is safe to look directly at the eclipse is during the total eclipse phase when the moon directly blocks the sun. This phase only happens within the path of totality shown on this map.
The 70-mile-wide path of totality spans from Oregon to South Carolina, so for people viewing the celestial event in Washington, you will need to wear special-purpose solar filters like eclipse glasses or hand-held solar viewers the entire time.
If you are thinking about just wearing sunglasses, think again. Sunglasses are not safe to wear when looking at the sun during an eclipse. Proper eyewear features lenses with thin layers of aluminum, chromium, or silver to reduce the intensity of the light radiation.
Here is what to look for when buying eclipse glasses.
Look at who made the glasses. According to NASA, these five manufacturers have certified their eclipse glasses and hand-held solar viewers meet the ISO 12312-2 international standard: American Paper Optics, Baader Planetarium, Rainbow Symphony, Thousand Oaks Optical and TSE 17. On the glasses themselves, look for the ISO icon to make sure it has the reference number 12312-2.
If the lenses are scratched or wrinkled, do not use them because they are no longer safe for viewing the eclipse. If you normally wear eyeglasses, put the eclipse glasses over them or your hand-held viewer in front of them.