This question arose when I thought that on Normal Days, at least I have observed bright sun while going outside, going to office, in park etc. for less than a second. It happens almost daily. Not deliberately but that's how things work I guess. Similar example is playing cricket. Many times sun comes in the way of ball in the air and again I have a glimpse of sun. To me, it is very common as I've seen in international cricket matches on TV.
On the other hand, in case of the days of Solar Eclipse, on one or two occasions, when the sun wasn't very bright due to clouds, I've deliberately observed the partial eclipse just for a glimpse, just to confirm it's actually cut. And I confirmed it. (How fast it was? It was not like I stood still and observed the sun for less than a second and then closed eyes. It was like this: I started moving my head and sight from earth surface and in a faster way moved my head towards sun and without any break, stopped at safe location on earth again where there was no sun). And it did literally no harm to me.
So my doubt is:
Why there's so much theories that you must not stare sun even for less than a second or even a glimpse by mistake? If you see news on eclipse day, you'll see full news about this. But on any other normal day, no such news. Is there something special, something more bright on solar eclipse day? Will it damage eyes?