How to explain to computer "engineers" ... In an eclipse (without clouds), every pixel of the sun that is exposed is just as bright as the sun normally is. Therefore it delivers the same burning power onto the corresponding coordinates of your retina. The other factor is that when overall light is dimmer, your eye iris opens wider and lets more light in, so, even worse. A triple threat is that your eye opens wider to look at something interesting.
So as soon as one tiny piece of sun peeks through a break in the wall of a moon crater ("Bailey's Beads"), sniff for that distinctive odor of roasting eye meat.
But don't you look at the sun normally every day anyway? Um, no. You don't look AT the sun. You look towards it, but not at it. Or else you have crispy black patches burned into the back walls of your eyeballs.