Solar Eclipse Safety

Solar Eclipse Safety

On August 21, 2017, for the first time in 99 years, a total solar eclipse will trace a path along 14 states across the continental United States. From Oregon to South Carolina, certain states will experience more than two minutes of darkness in the middle of the day when the moon completely blocks the sun. This celestial event will be viewed and explored from different vantage points, and should be done safely.

Safety Recommendations

  • Never look directly at the sun without special-purpose solar filters or viewers (“eclipse glasses”). “Special-purpose” means specifically designed for safely looking directly at the “everyday sun,” because the filters are many thousands of times darker than regular sunglasses.
  • Welding filters are only safe for viewing the sun if they are Shade 12 or higher.  If you’re unsure about the filter’s shade number, do not use it to look at the sun.
  • Purchase solar filters or viewers from the American Astronomical Society’s list of Reputable Vendors: https://eclipse.aas.org/resources/solar-filters.
  • Do not use solar filters or viewers if:
    • They do not have the ISO 12312-2 compliance label. 
    • You are unsure about their quality.
    • They are torn, scratched, or punctured.
    • The filters are coming loose from the frames.
  • Some solar filters or viewers may have printed warnings to discard it after it has been used for more than 3 minutes.  According to NASA, such warnings are outdated and do not apply to viewers that are compliant with the ISO 12312-2 standard that was adopted in 2015.  These can be reused indefinitely, unless they are somehow damaged.
  • According to the American Astronomical Society, “You shouldn't be able to see anything through a safe solar filter except the Sun itself or something comparably bright…If you can see lights of more ordinary brightness through your eclipse glasses or handheld viewer, and you're not sure the product came from a reputable vendor, it’s no good…If you glance at the Sun through your solar filter and find it uncomfortably bright, out of focus, and/or surrounded by a bright haze, it’s no good.”
  • Stand still and cover your eyes with your eclipse glasses or solar viewer before looking up at the bright sun. After looking at the sun, turn away and remove your filter — do not remove it while looking at the sun.
  • Do not look at the sun through a camera, a telescope, binoculars, or any other optical device while using your eclipse glasses or hand-held solar viewer — the concentrated solar rays will damage the filter and enter your eye(s), causing serious injury.
  • If you normally wear eyeglasses, keep them on. Put your eclipse glasses on over them, or hold your handheld viewer in front of them.

Special Notes

  • Since California will only have a partial eclipse, appropriate eye protection must be worn at all times when looking at the sun.  It is not safe to look directly at the sun without a special-purpose solar filter.
  • Beware of counterfeit glasses purchased from vendors not listed on the Reputable Vendors list, even those marked with the ISO 12312-2 compliance label.
  • For methods of indirectly looking at the eclipse, via projection (pinhole or optical), read the information on the American Astronomical Society’s webpage – https://eclipse.aas.org/eye-safety/projection.

Road Safety

  • Limit distractions while driving and pay attention.
  • Be aware of possible distracted drivers during the event.
  • Do not park on the highway (parking a hot vehicle over dry vegetation could start a fire).
  • Do not take a picture while driving.
  • Do not wear your eclipse glasses while driving.

Resources