Despite many warnings about the possibility of permanent eye damage—and, in one case, the advice of a presidential aide—a lot of people ended up looking at the sun during Monday's eclipse without the recommended solar filter. Jacob Chung, chief of ophthalmology at New Jersey's Englewood Hospital, tells USA Today that people who looked at the sun for a few seconds are probably fine, but 10 seconds could cause damage, and 20 seconds is "definitely too long." He says people with damaged eyes won't feel pain, but they may begin to experience blurry vision within a day or two. Experts recommend that people worried about eye damage print off an Amsler grid and use it to check for vision problems.
University of Waterloo optometry professor Ralph Chou tells NPR that symptoms won't be apparent for at least 12 hours. After that, he says, people might experience "blurred vision, where the very center of the vision might have a spot, or multiple spots, that were missing in their vision—that were very, very blurred. Around it, there might be some clear spots." He says people worried about damage should see an optometrist, and that while wearing sunglasses won't mitigate the damage, it will make vision more comfortable during recovery. BuzzFeed has rounded up tweets from people complaining about sore eyes after the eclipse. "My eyes melted," claims one person. (Read more eclipse stories.)