Why is a solar eclipse more harmful to your eyes?

Factual Questions
1

So I’ve been wondering this for years, and I still can’t find a single source that actually explains why looking at a partial solar eclipse is so dangerous compared to looking at the non-eclipsed sun.

Initially I figured that maybe they think that people are more likely to stare at the sun during an eclipse, and that’s where the added risk comes from, but a lot of news stories have lines like this:

“‘Even just momentarily looking at eclipse can cause solar burns on the retina,’ said Dr. Greg Hill, optometrist with Avera Medical Group Eye Care.”

I’ve momentarily looked at the sun many, many times during my life and my retinas are fine. Is the eclipsed sun more dangerous than regular sun or not?

2

I think that’s basically the answer, but also what exactly we’re fixated on. It’s probably easier to fixate on the black part, while the retinas are being damaged by what’s remaining of the sun. I found this:

http://web.williams.edu/Astronomy/IAU_eclipses/look_eclipse.html

One person’s “momentarily” can be a little longer than another’s.

3

And those momentary glances at the Sun have done damage to your eyes. Not much, and most of it probably recovered, but still some. The cumulative effect of all of those momentary glances is one of the reasons why eyesight degrades with age.

4

Ah, thank you. Your Google-fu is stronger than mine.

5

We’ll be wanting our eyes in their best condition for the two minutes of totality … seeing the partial phases ain’t worth the risk of missing the Main Show … and during totality eye protection is not necessary … and that’s only during totality …

6

But the wise individual does not take off the eye protection lest he misjudges the moment when they are needed again.

7

The wise and extra cautious individual.

However, with the Interwebz available to all and sundry nowadays it is possible to know the exact times of totality at the exact location you are viewing from. With a good watch and taking great care one can watch totality with the naked eye and have the goggles safely back on once totality ends.

This is a link to a to map where I think you can check those times but it looks like the server is overloaded now so I couldn’t check (but I’ve seen it before).

On the subject of that guy’s map page… he created an overlay to Google maps that gives all kinds of info about the eclipse. But as we get closer to the event, his server is likely to get swamped–as it is right now, I think. Why hasn’t Google themselves created a map like this? Or have they?

I mean… Google makes goofy interactive Doodles for National Chipmunk Secretary’s Day… surely they would make a nice interactive map for a once-in-a-lifetime eclipse, wouldn’t they?

8

The wise individual might put on his glasses ten or fifteen seconds earlier than needed, just to be sure, but if you leave them on for the entire totality period, you’ll be missing one heck of a show.

9

Better to download an app such as ** solar eclipse timer** that provides a audible countdown and knows your location by GPS…