You probably know, but looking into the Sun is not something you should ever do if you value your vision. The corneas in our eyes cannot withstand the UV radiation put out from the sun, even if it is 150 million kilometers away, according to Science Alert.
On the other hand, looking at much more distant stars through a telescope can be a fun learning experience, but you probably should never look at the closest star, the Sun. One astronomer wanted to take an extra step to show viewers why they should never try to observe the Sun through a telescope. Using a pig eye, he held it up to the looking glass on the telescope for only 20 seconds, and the damage was incredible.
WARNING: Do not watch if you are squeamish.
Pigs eyes are the most similar to humans, so you can be sure that what happened in the video above will happen if you look at the Sun through a telescope.
After only 20 seconds, the pig's eye had a giant hole in it, and the retina was severely damaged.
"If this was a human eye there would almost certainly be some pretty severe damage, and that is why it's a very, very bad idea to look at the Sun through the eyepiece of a telescope." ~ Mark Thompson
We can often hear warnings over and over again, but sometimes it takes the experience or the visual of something to seal it in your brain that you definitely won't be doing that. If for some reason you do want to look at the Sun, you can build yourself a solar projection box, which casts the light onto a white sheet so you can view it without harm.
This video may be a helpful tool to show to kids to further teach them that looking into the Sun is a really, really bad idea. If you want to view the Sun, make sure you have the proper equipment and do it safely, because no one wants to go blind.