On April 8, many parts of North America will experience a total solar eclipse (path of totality), when over the course of a few hours the moon completely blocks the sun. While Massachusetts will not witness the total effect, the 93% coverage anticipated in the Boston-area will still be an exciting event!
Even though it can be tempting to put on your regular sunglasses and head outside, staring directly at the sun can cause irreversible damage to the eye due to the strong amount of UV light. Looking at the sun without the correct eye protection can result in a burn of the retina and cause permanent blindness.
Your regular sunglasses or homemade filters, no matter how dark, will not protect your eyes when looking directly at the sun. You will need eclipse glasses with special filters that are one thousand times darker than standard sunglasses. Make sure your eclipse glasses are marked with the ISO 12312-2 designation, the worldwide standard, and are purchased from a reputable source. The American Astronomical Society website has a list of approved vendors.
Also, be sure your eclipse glasses are not scratched, and don’t use them if you see any damage. If you are viewing with children, make sure they are using the glasses properly throughout the event. Do not look at the uneclipsed or partially eclipsed sun through unfiltered binoculars, camera or telescope binoculars or other similar devices. Remember that the ISO 12312-2 designation does not correspond to solar filters meant to fit over the front of these types of optical devices.
Last of all, do not despair if you do not have eclipse glasses. An indirect viewing technique called a pinhole viewer can easily be made with simple household supplies that will spare you any direct viewing of the sun. This fun science project can be found on the NASA website.
And remember, while the solar eclipse is a unique event requiring special precautions—you should always keep your eyes safe every day by wearing sunglasses with lenses marked with a UV400 rating.
