On August 21, a total solar eclipse will touch the U.S. mainland for the first time since 1979. The eclipse will follow a path that crosses the country from Salem, Oregon to Charleston, South Carolina. Tens of millions of people who live within a 70-mile radius of every point along its cross-country track will be able to witness the total solar eclipse (the sun completely blocked by the moon) while millions of others outside of it will enjoy a partial eclipse. During the period of total eclipse, the moon fully covers the sun for a few minutes and the sun glows like a halo around it. The 2017 eclipse is predicted to be the most-viewed solar eclipse ever in the United States. In middle Tennessee, we are fortunate to be in one of the best viewing areas and will be able to enjoy the total solar eclipse. In fact, Nashville is the only major city that will experience the total eclipse with the full view!
This is a very exciting event for our city, but it is very important to view this 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 (the tissue at the back of your eye) 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 often called eclipse glasses. These are glasses that meet a worldwide standard known as ISO 12312-2. This standard ensures the exposure of visible light is reduced to a safe and comfortable level, as well as also blocking UV and IR radiation. To verify your glasses are safe, ensure they are labeled as meeting ISO 12312-2 standard. To date, four manufacturers have certified that their glasses meet the standard for these products: Rainbow Symphony, American Paper Optics, Thousand Oaks Optical, and TSE 17. The frames of these special glasses are often made of cardboard and can thus be obtained inexpensively, but as long as they are labeled to meet the standards and are from one of these manufacturers, they are safe. However, it is very important to ensure that your glasses are not torn, punctured, or scratched – in which case they should be discarded. Ordinary sunglasses and homemade filters are never safe for looking at the sun.
To enjoy the eclipse safely, be sure to follow any instructions included with your solar filters. Before looking at the sun, cover your eyes with your solar filters then direct your eyes to the sun. After looking away, you can safely remove your filters. The only time that it is safe to view the sun without the filters is during the few minutes of total eclipse. When the moon completely covers the sun, and it suddenly goes dark, it is safe to remove your filters. 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 incredibly important not to view the uneclipsed sun through an ordinary camera, telescope, or binocular – even with a solar filter. The intense solar rays are magnified in these devices and this can damage both the solar filter and your eyes. Seek the expert advice of an astronomer if you desire to view the eclipse with anything other than the protected naked eye, such as a camera. 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.
It is important to note that having had any of the laser vision procedures (SMILE, LASIK, Kamra, Raindrop, Forever Young Lens or laser cataract surgery) does not reduce at all your risk of eye damage caused by watching the solar eclipse, neither does wearing contact lenses of any kind or glasses.
Because of the risk of eye damage, it is important for an adult to supervise children viewing this event. The adult can walk children through the steps to safely view the sun with the filters, as they may not understand the consequences if they don’t follow the safe viewing practices. It is important to know that with the appropriate protection viewing this incredible astronomical phenomenon is perfectly safe. However, if you experience any problems with your eyes or vision after the eclipse you should consult an optometrist or ophthalmologist immediately.
About Dr. Ming Wang
Dr. Ming Wang, Harvard & MIT (MD, magna cum laude); PhD (laser physics), is the CEO of Aier-USA, director of Wang Vision 3D Cataract & LASIK Center, and one of the few laser eye surgeons in the world today who holds a doctorate degree in laser physics. He has performed more than 55,000 procedures, including over 4,000 on doctors. Dr. Wang is currently the only surgeon in the state who performs 3D SMILE & 3D LASIK (18+), 3D Kamra & 3D Raindrop (45+), 3D Forever Young Lens (50+) and 3D Laser Cataract Surgeyr (60+). Dr. Nathan Rock OD helped prepare this manuscript. For more information about how to protect your eyes during the solar eclipse and how to take care of your eyes if indeed there is any solar damage, visit wangcataractLASIK.com or email firstname.lastname@example.org.