As millions of people across the country prepare to look up to the sky later this month and watch as the moon slowly blocks out the sun during the total solar eclipse, doctors and officials are warning onlookers that not using proper eye protection could lead to permanent vision damage.
With less than two weeks to go until the first total solar eclipse in 38 years occurs in the continental United States, the Sumner County Convention and Visitors Bureau has received more questions about eye safety than any other issue, according to Executive Director Barry Young.
"It is probably the highest priority during the eclipse because people don't normally think about looking right at the sun on a normal day," Young said. "They know not to do it, but because the eclipse is so rare people haven't really heard much about it until recently."
Staring at the sun without using property eye protection, even for a short time, can result in damage to a person's retina called solar retinopathy, according to Dr. Ming Wang. The injury, which can be temporary or permanent, would result in blurry or missing spots in vision depending on the level of severity.
"This damage can occur without any sensation of pain, since the retina does not have pain receptors," Wang said. "It generally will affect both eyes and symptoms would (be) present without hours of exposure. In worst cases, it could lead to permanent partial blindness."
NASA estimates that more than 300 million people could potentially directly view the total solar eclipse in North America when it crosses 14 states from Oregon to South Carolina on Aug. 21.
The only safe way to look directly at the sun is with special-purpose solar filters such as eclipse glasses or a handheld solar viewer, according to the federal agency. Ordinary sunglasses, even very dark ones, should not be used since they will not provide the necessary eye protection when looking at the sun.
Eclipse viewing glasses and handheld solar viewers should meet the following criteria:
- Have certification information with a designated ISO 12312-2 international standard
- Have the manufacturer's name and address printed somewhere on the product
- Should not be used if they are older than three years or have scratched or wrinkled lenses
- Homemade filters should not be used
Individuals should wear eye protection whenever looking directly at the sun - even during the partial eclipse that will take place for about 90 minutes before and after the total eclipse on Aug. 21.
It is only safe to view the total solar eclipse without glasses, which is when the moon completely blocks out the sun, according to Young. In Sumner County, that will begin at approximately 1:27 p.m. and last for 2 minutes and 40 seconds.
"The key thing to remember is that anytime there is any part of the sun showing you have to wear the glasses to look up at the sun," Young said. "There have even been cases where people have gotten so excited about an eclipse that they've forgotten to put the glasses on and they have just looked right up at the sun."
Eclipse glasses are being sold at many local retailers with some being given away during viewing events later this month while supplies last.
It is also important not to view the uneclipsed sun through an ordinary camera, telescope or binoculars even with a solar filter since the "intense solar rays are magnified in these devices" and can damage both the filter and your eyes, according to Wang.
Adults should also make sure to supervise children viewing the eclipse. Anyone experiencing problems with their eyes or vision after the event should consult an optometrist or ophthalmologist immediately.
In addition to eye safety, Young said those who plan to attend outdoor eclipse events across the county should also make sure to wear sunscreen as well as stay hydrated.
"Most festivals have big tents and shade, but this is a different kind of event where you want to have a wide open space and you want to be out in the sunlight," Young said about the upcoming viewing events. "People are really excited and some have even waited years for this."