What specifically makes solar eclipses dangerous to watch with the naked eye directly?

Answer 1

Danger to the eye is from heat ( infrared radiation ), UV ( ultraviolet radiation ), and from excessive blue light. The heat risk is perhaps the best understood, since we are familiar with using a lens to focus the sun to burn paper.
A momentary glance, such as we do occasionally on a sunny day, does indeed focus a very intense image of the sun on the transparent neural tissue at the back of the eye, the retina, and a highly absorbent layer just beyond, but we have a reflex to avert our eye and the heat buildup is brief and little damage results.
If one closes the eye after such a chance event, one will note a series of bright 'after images' of the sun staggered irregularly, indicating the eye's protective motion during the glance.
Since there is nothing novel to see, a simple disk, no specific fixation results. UV radiation can cause 'sunburn' to the cornea or outer surface of the eye, just like sunburn to the skin - same mechanism, similar damage, but for the eye it results in pain and vision loss. The retina is at risk from a very small part of the UV that is transmitted through the ocular media and lens. This risk is greatest for young eyes, and in general adults beyond 30 years of age have enough yellow in the lens and absorption in the media that UV after atmospheric absorption is less of a problem than the heat. The least well understood risk is from blue light that seems implicated in biochemical damage to receptor cells and their environment in the sensitive neural tissue.

Answer 2

The same thing that makes looking directly at the sun with the naked eye dangerous. During a solar eclipse, people are tempted to look up and watch the sun's corona around the moon, but what they fail to realize is that the earth is rotating at an incredible speed and the 'safe' period to look up with the naked eye is something on the order of microseconds -- a split second in time when the sun's face is completely covered by the moon, and before the sun becomes visible on the other side of the moon. And at that point, you are looking directly at the sun with the naked eye.
In fact, most eclipses don't even have this microsecond window of safe viewing because the eclipse is not always total.
It's safer to watch the eclipse through a reflected image, or through specially coated smoke glass lenses.

Answer 3

The truth is that even though the sun is being blocked out by the shadow of the moon. You can still cause damage to your eyes from the suns x-rays and other radiation. The sun is never fully eclipsed and you usually still see the ring of the sun around the shadow. This will still damage your eyes as much as looking into it during a regular day.

Answer 4

If you look at the sun for a long time, the strong rays are focused by the lens in your eye and damage your retina, like you can burn an old leaf of piece of paper with a magnifying glass lens, ya know? And don't try it, because this really does happen and it's not reparable. I think it doesn't even feel painful while it's happening, so then you have serious vision damage before you realize it. Please don't take any chances!

Answer 5

Its the UV from suns rays,because they dont get filtered out,only if your wearing sunnies!!

Answer 6

Well, you're looking at the sun. You can't stare at the sun for very long can you? Same thing.

Answer 7

Well Gaaawwwwly...the sun's rays will burn a hole in your eyes