You can safely take a picture of the solar eclipse with your iPhone - but don't use the camera to watch it
As you may have heard, a total solar eclipse is making its way across the continental US today.
You need to wear protective solar eclipse glasses to safely watch the moon cross in front of the sun, as the sun's powerful rays can cause serious eye damage if they are viewed directly. (There are good ways to watch the event without staring at the sun if you haven't been able to find glasses.)
But one method of trying to watch without directly looking should be avoided, according to Dr. Tongalp Tezel, a retina expert at Columbia University Medical Center.
Don't try to watch the eclipse through the front-facing selfie camera on your phone, Tezel said in a news release.
You can take photos of the eclipse with your phone camera without damaging the sensor, as long as you don't have a zoom lens attached - there's no danger to the camera itself.
But your phone screen can reflect ultraviolet light back into your eye, according to Tezel, potentially causing the same damage - solar retinopathy - that looking at the sun itself can cause. Even taking a selfie without wearing eclipse glasses could reflect the sun's light back into your eyes, potentially elevating the chance of a risky moment.
"Many people will think it's safe to take a selfie with the eclipse in the background because they aren't looking directly at the sun," said Tezel. "What they may not realize is that the screen of your phone reflects the ultraviolet rays emitted during an eclipse directly toward your eye, which can result in a solar burn."
According to NASA, symptoms of injury caused by sun damage usually include blurred vision, dark or yellow spots, pain, or loss of vision in the center of the eye. That sort of damage can make it hard or impossible to read or to focus on whatever is right in the center of your view.
For some people, vision recovers within 24 hours - but there could still be damage to the eye, which could result in later problems. In general, people recover as much vision as they are going to within six months of the event, according to the American Academy of Ophthalmology.
If you are within the 70-mile-wide band of totality, you can safely remove your protective glasses once the sun is totally covered. You'll know it's time because you won't be able to see anything with those glasses on. But as soon as beads of light start to re-appear, it's time to protect your eyes again. Even 1% of the sun is enough to cause damage.
If you can't find eclipse glasses, we'd recommend making a simple pinhole viewer to watch safely.