On August 21, at 1:28pm, residents in middle Tennessee will be able to see a total solar eclipse (the sun completely blocked by the moon), the first such event that touches the U.S. mainland in quarter a century.
It is very important to view the solar eclipse safely with proper eye protection to avoid damage to your eyes. If you stare at the sun without protection, even for a short time, you may experience damage to your retina called "solar retinopathy." The injury can be temporary or permanent and would result in blurry vision or missing spots in the vision, depending on the level of severity. This damage can occur without any sensation of pain, since the retina does not have pain receptors. It generally will affect both eyes and symptoms would present within hours of exposure. In worst cases, it could lead to permanent partial blindness.
There is only one safe way to look directly at the sun. This is through special purpose solar filters which are called eclipse glasses. These are glasses that meet a worldwide safety standard known as ISO 12312-2 which ensures that the exposure to UV and IR radiation is reduced to a safe level. You need to verify that your glasses are labeled as meeting ISO 12312-2 standard. To date, four manufacturers have certified that their glasses meet the standard: Rainbow Symphony, American Paper Optics, Thousand Oaks Optical, and TSE 17. Ordinary sunglasses and homemade filters are never safe for looking at the sun.
On August 17, Thurs 6:30pm, we will conduct a free public educational seminar about the important things that everyone should know about how to view solar eclipse safely. Each attendee will receive a free pair of ISO 12312-2 standard eclipse glasses.
At the seminar, we will demonstrate how to follow the instructions included with your eclipse filters. Before looking at the sun, cover your eyes with your eclipse glasses then direct your eyes to the sun. After looking away, you can safely remove the filters. The only time that it is safe to view the sun without the filters is during the few minutes of total eclipse. This will last for slightly more than two minutes in Nashville. However, as soon as an arc of sun begins to appear slightly you must immediately use your solar filters again.
It is important not to view the uneclipsed sun though an ordinary camera, telescope, or binocular - even with a solar filter. The intense solar rays magnified in these devices can damage your eyes. If you do want to take an iPhone photo or a video of the solar eclipse, you should do so only during the complete eclipse (which lasts only 2 minutes) even with your proper solar filter.
Having had a laser vision procedure (SMILE, LASIK, Kamra, Raindrop, Forever Young Lens or laser cataract surgery) does not reduce your risk of eye damage caused by watching the solar eclipse, neither does wearing contact lenses or glasses.
Because of the risk of eye damage, it is important for an adult to supervise children viewing this event. If you or your children experience any problems with your vision after the eclipse you should consult an optometrist or ophthalmologist immediately.