We are hearing constantly now about not looking at the sun during an eclipse. But before we had our current understanding, before a media to spread the message, and before special eclipse glasses, wouldn't curious farmers and villagers have been watching the entire event? It seems like there should be stories of people being wiped out when farms failed when the farmers and their families all went blind, of large amounts of blinded people without means of support after a total eclipse. If this occurred, it seems as though it would have become a part of folklore or myth.
Edit: Thanks! Those answers make perfect sense. I assumed the media frenzy was overblowing the whole risk, since I had not heard of this occurring. If they were right, animals, too, who happened to look up at that moment would be blinded, and there are not stories of herds of cows, for example, suddenly having an increase of blind members. Logic wins on this one.
Staring at the sun for a short period of time does not necessarily cause permanent blindness. [This] (http://scienceline.ucsb.edu/getkey.php?key=3269) webpage hosted by UC Santa Barbara gets into what we know about the effects.
Obviously, no one has done a study to measure the exact time before damage or blindness occurs, but doctors collect information after events like the 1999 solar eclipse, when people who stared directly at the sun for several minutes went to see their doctor. In one study, about half had permanent damage.
Based on the information that we know about staring at the sun, it would seem unlikely that an entire village would ever go blind all at once by staring at an eclipse.
No one has ever been blinded or had their vision damaged from viewing a total eclipse. During a total eclipse, the sun itself is completely hidden behind the moon, and what you see is the solar corona. The corona is only about as bright as a full moon and has no potential for any kind of eye damage.
Of course, every total eclipse is preceded and followed by a partial eclipse. And people outside the zone of totality only see a partial eclipse.
The partial eclipse is where the danger lies. But even a partial eclipse is very unlikely to completely blind anyone.
Look at the sun for a moment (a brief moment!) and notice what a small part of your vision it occupies. Or more safely, look at a full moon, as it is about the same apparent size as the sun - the very coincidence that allows us to experience total solar eclipses.
If you could somehow force yourself to stare directly at the sun long enough, it would destroy a portion of your retina - but only the small part of it where the image of the sun is focused.
Of course the area destroyed would be the center of your vision, the fovea, where you normally see the finest detail. You would have a blind spot, one that may prevent you from ever seeing fine detail again. But you would still have the rest of your vision.
Thankfully, it is difficult to force yourself to stare at the sun under normal conditions. It hurts, it makes your eyes water, you squint and you quickly look away.
The problem with a partial eclipse is that the overall amount of sunlight is so much less that these normal reactions don't occur. But the remaining crescent of light is just as intense as ever - and the sight is so fascinating that you just might be tempted to stare at it.
If you stared long enough, you would have a crescent-shaped blind spot in the center of your vision. But the rest of your vision would still be there.
Think about a village in earlier times. Not every job required perfect vision. Someone with a blind spot in their fovea may no longer be able to be a seamstress or an arrow-maker, or other work that required finely detailed vision. But they could still see well enough to drive a plow, grind the grain, do the laundry, or any number of other useful tasks that would let them continue to be a productive member of their community even after losing their fine central vision.
And it's a fairly safe bet that they told their children and other community members, "Don't do what I did! Never stare at the sun, especially when it looks like a crescent moon!"
Here is a report from a reddit user who believes they suffered vision damage in the '90s from viewing a partial eclipse. This person can still see, although they have lost a small portion of their vision.
Today, as you mentioned, we have news media to warn people of the danger. Unfortunately, news is often reported by people who have no clue what they are talking about. If you've ever seen a news report about any technical topic that you are deeply familiar with, you may have noticed that they didn't get it right - and may have gotten it very wrong. News media is in the business of selling the news, and not necessarily the business of finding and telling the truth. Fear is always one of the best ways of selling the news.
I went to Oregon to see the 1979 total eclipse, and I found the local news media running a fear campaign telling people their vision would be ruined if they even dared to peek at the total eclipse. Which as I explained above is perfectly safe; it's the partial eclipse that is dangerous.
As a result, schools adjusted their hours to make sure children would be inside and protected from this dangerous eclipse. They may have protected the children, but they also kept them from an experience of a lifetime. Anyone who has ever observed a total eclipse, as I have, has likely been awestruck by the experience.
One astronomer wrote about how he was denied the chance to see the 1979 total eclipse as a child because of the fear-based thinking the news media promoted.
I don't have a link to a news report from that era, so I hope the mods will forgive me for citing a more recent report from KPTV in Portland, Oregon. This report is exactly the same kind of shamefully misleading coverage that was broadcast in 1979. In the video segment, they repeatedly show pictures of a total eclipse while talking about the dangers of the partial eclipse - as if there were no difference between the two!
Instead of educating people with the truth, they spread a false message of fear.
If you are fortunate enough to be in the path of totality for Monday's eclipse, NASA has an excellent page on eye safety with a very conservative approach to viewing the total eclipse safely.