This video will make you think twice before you look at the sun.
Astronomer Mark Thompson took a pig's eyeball and held it up to the lens of an 18 millimeter telescope pointed directly at the sun. The eyeball begins to burn after just 20 seconds and leaves a visible hole right through its core, as seen in a video Thompson posted on his YouTube page.
Thompson dissected the pig eyeball after the experiment and showed visible nerve damage that may have been caused by the sun.
"If this was a human eye, there would almost certainly be some pretty severe damage," the scientist said in the video. "That's why it's a very, very bad idea to look at the sun through the eyepiece of a telescope."