When the moon fully eclipses the sun, it's not just the sky that changes. Your eyes do, too. When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works.

Sitting in the grass of a Tennessee state park, Tracy Gregg felt the air grow cold as the late afternoon light she'd been bathing in suddenly faded. It was August 21, 2017, the date of a total solar ...