On August 21, 2017 a solar eclipse will envelope the nation for 2-3 hours, while a small, 70 mile sliver from Salem, Oregon to Charleston, SC will experience a total solar eclipse for the first time since 1979. Dubbed "The Great American Eclipse" this eclipse is noteworthy for its cross-country path of totality that will be visible from most Americans' backyards. However, watching a solar eclipse isn't as simple as looking skyward. Looking directly at the sun is unsafe except during the brief totality. And that only happens in a small area. Consequently, while millions can -and will- watch the eclipse, not all are aware of how to safely do so.
Solar retinopathy, or photic retinopathy, can occur when a person stares at the sun, causing retinal tissues to be damaged at the fovea, and resulting in a mild-to-moderate visual acuity deficit and central or paracentral scotoma. Captain Tyson Brunstetter, OD, PhD, a U.S. Navy doctor working with NASA says the single greatest risk to viewing a solar eclipse comes from nonionizing (low energy) radiation, the visible and infrared light that easily passes through the eye and is focused on the retina. The ramifications of improperly viewing a solar eclipse can be immense and permanent and because there are no pain receptors in the retina, this damage can occur without any sensation of pain.
The only safe way to look directly at the uneclipsed or partially eclipsed sun is through eclipse glasses or filters.
Stay tuned next month on DIY indirect viewing devices.
--Information for this article from Myron Wasiuta, OD, AOA Focus magazine, May 2017