Can you really go blind by staring at the Sun?

Source: http://www.sciencefocus.com/qa/can-you-really-go-blind-staring-sun
Published: Aug 21, 2017
Author: Steven A Collins
Post Date: 2017-08-21 10:54:04 by no gnu taxes
Views: 9038

It’s possible, but the hazard is often exaggerated. Even at midday, a normal eye will only let in enough light to heat the retina by about 4°C. You need at least 10°C to cause thermal damage. Looking at the Sun during an eclipse for more than a minute can cause damage, because your pupils are more dilated during this, but it doesn’t result in total blindness and isn’t usually permanent. If the Sun is within 10 minutes of setting below a sea-level horizon, the more dangerous short-wavelength light is absorbed by the atmosphere and it should be quite safe to look at the Sun.

Post Comment   Private Reply

#1: Vicomte13    To: no gnu taxes (#0)

18 seconds. If you look directly at the sun for more than 15 seconds, you will burn a permanent spot on your retina that will never heal. A GLANCE probably won't destroy your vision, but what is going on up there is fascinating, and draws you in, and you really LOOK - and then you're blind for life.

It isn't just during an eclipse. Stare at the sun on any day, and you'll burn your retinas blind. But who stares into the Sun? It's when there's an eclipse that the problem comes, because everybody wants to LOOK, and when looking, people are drawn to stare. And that will leave you blind.

Vicomte13 posted on 2017-08-21 11:02:08   Reply   Private Reply


#2: rlk    To: no gnu taxes (#0)

Can you really go blind by staring at the Sun?

Try it and find out...

rlk posted on 2017-08-21 11:03:41   Reply   Private Reply


#3: misterwhite    To: Vicomte13 (#1)

That's an old wives' tale. How can something 93 million miles away hurt you?

misterwhite posted on 2017-08-21 11:21:51   Reply   Private Reply


#4: Tooconservative    To: Vicomte13 (#1)

You overlook that significant damage can be caused by sunburn to the inner eye. And no pain receptors to warn you of the danger.

18 seconds. If you look directly at the sun for more than 15 seconds, you will burn a permanent spot on your retina that will never heal.

I do think this is a little overhyped.

Tooconservative posted on 2017-08-21 11:51:24   Reply   Private Reply


#5: VxH    To: no gnu taxes (#0)

Dunno 'bout that - but worse things can happen if the gods don't signal their appeasement by making the Sun go dark...

VxH posted on 2017-08-21 12:39:32   Reply   Private Reply


#6: Vicomte13    To: Tooconservative (#4)

I do think this is a little overhyped.

Yes. A one second, two second glance isn't going to do anything. But 15-18 seconds will leave you with a blind spot for life. That's not a huge margin. I'll go out at the eclipse and glance at it when it happens, but that's just it - a glance - no staring at it.

Stare at the midday sun for more than a few seconds on any day and you will be blind for life.

Vicomte13 posted on 2017-08-21 12:50:25   Reply   Private Reply


#7: Tooconservative    To: Vicomte13 (#6)

You are cautious. I can't say overcautious because we shouldn't encourage anyone to ever stare directly at the sun. Nothing good can come from it.

Tooconservative posted on 2017-08-21 14:27:33   Reply   Private Reply


#8: no gnu taxes    To: Vicomte13 (#6)

No, I won't be staring at the sun. I see no useful purpose in it and it does nothing good for you. However....

................................

http://boards.straightdope.com/sdmb/showthread.php?t=102708

I have done some research on this topic. From what I have found, no one has ever gone totally and permanently blind from looking at the Sun. Solar retinopathy (retinal damage from looking at the Sun) is, however, a complicated issue.

The damage comes mostly from ultraviolet light which can damage chemicals in your eye. Many people claim erroneously that infra-red can cook your eye, but this is almost certainly not true; IR light is not absorbed well by your eye. In general, your pupil constricts so rapidly that there isn't time to hurt your eye easily. Staring at the Sun can indeed damage your retina, but there are many cases of full recovery from people who have looked at the Sun for long periods of time. Interestingly, the pupil blocks just barely enough light (on average) to prevent damage; so in some of the population the pupil does not constrict enough. The lens also yellows with age, protecting older people more from the UV light. Therefore, children are more susceptible to damage than adults.

All in all, better safe than sorry; avoid staring at the Sun.

The reason solar eclipses are dangerous is because during totality the pupil dilates, letting in more light since the Sun is blocked. When the Moon slips off the Sun, even the thin sliver of solar surface can be enough to flood your retina with damaging photons, since the pupil is wide open.

A very interesting website with a lot of information has been put together by astronomer Andrew Young. He also puts to rest the legend that Galileo went blind by looking at the Sun; he has excellent counter-evidence for that.

no gnu taxes posted on 2017-08-21 14:46:17   Reply   Private Reply


#9: Willie Green    To: Tooconservative (#7)

we shouldn't encourage anyone to ever stare directly at the sun. Nothing good can come from it.

Willie Green posted on 2017-08-21 15:08:28   Reply   Private Reply


#10: Vicomte13    To: Tooconservative (#7)

I went and looked at it directly. Only for a few seconds, enough to see. Pretty cool. My eyes weren't too dazzled.

Vicomte13 posted on 2017-08-21 15:48:27   Reply   Private Reply


#11: Vicomte13    To: Tooconservative (#7)

I can't say overcautious because we shouldn't encourage anyone to ever stare directly at the sun.

"If I look hard enough into the setting sun, My love will laugh with me until the morning comes." - Rolling Stones

Vicomte13 posted on 2017-08-21 15:52:27   Reply   Private Reply


#12: Hondo68    To: Vicomte13, Blind Trumpkins (#11)

http://ijr.com/the-declaration/2017/08/953203-jeff-sessions-watching-solar-eclipse-pure-thing-internet/

Hondo68 posted on 2017-08-21 18:36:20   Reply   Private Reply


#13: misterwhite    To: no gnu taxes (#0)

Can you really go blind by staring at the Sun?

You're confusing that with masturbation.

misterwhite posted on 2017-08-21 18:59:35   Reply   Private Reply


#14: misterwhite    To: VxH (#5)

A very good movie. As was the Passion of the Christ.

misterwhite posted on 2017-08-21 19:02:01   Reply   Private Reply


#15: Vicomte13    To: misterwhite (#14)

Yeah. The "happy ending" was the arrival of the Spanish! Jeez Louise!

Vicomte13 posted on 2017-08-21 19:12:56   Reply   Private Reply


#16: Pinguinite    To: Vicomte13 (#15)

Yeah. The "happy ending" was the arrival of the Spanish! Jeez Louise!

Not sure if you're being sarcastic, but I'm sure the Spanish arriving at the end was not intended to be a happy ending. As per the movie title, it was more a revelation that the warring factions, while fighting amongst themselves, were oblivious to a greater threat that made their differences insignificant. It was an illustration of foolishness, and a message perhaps intended for the contemporary world.

Pinguinite posted on 2017-08-22 02:24:32   Reply   Private Reply


#17: Vicomte13    To: Pinguinite (#16)

Not sure if you're being sarcastic,

Ironic.

Vicomte13 posted on 2017-08-22 08:21:37   Reply   Private Reply


#18: Tooconservative    To: hondo68, Vicomte13, misterwhite (#12)

HotAir:

Eclipse glasses are for cucks

To cleanse the palate. What was the one rule every eclipse-watcher knew by heart this morning? Right — don’t look directly at it without special filtered glasses. (Except during the 90 seconds or so of totality, when it’s fine.) Newspapers are littered with stories today about imbeciles who did that in previous eclipses, believing they were invincible, and ended up paying the price. Many more imbeciles did it today as well, of course, and are also paying the price. Word circulated this afternoon that the president himself would observe the eclipse today from the Truman balcony of the White House, which naturally kicked off a round of speculation. Was he, er, going to wear the glasses? Or would he go full Trump? Remember, he hates following conventional wisdom.

Trump critics imagined the fallout if he decided to “go commando,” as it were:

id say theres about a 50% chance this happens later pic.twitter.com/dQ1zqZWxqv

— leon (@leyawn) August 21, 2017

Preview of tonight’s Tucker Carlson pic.twitter.com/DawbInUrWl

— Jason O. Gilbert (@gilbertjasono) August 21, 2017

He did, in fact, wear the glasses as the sun passed over D.C. — for the most part. But some of the still photos taken while he was on the balcony caught him sneaking glimpses without the protective eyewear, producing unintentionally hilarious photos that make it look like Trump was staring right into the heart of doom despite the omnipresent warnings not to do that. CNN (who else?) has no fewer than three pictures of Trump looking right at it. There was no totality in Washington rendering it safe to look, either. The sun was 81 percent obscured, still plenty visible enough to cause damage.

This is the moment Trump became president:

Trump looked at the solar eclipse without glasses on https://t.co/hyfMou0Cve pic.twitter.com/zUQmpOaHG4

— Business Insider (@businessinsider) August 21, 2017

Is the president blind now? Nah. I think it’s just a case of the still photos being deceptive. He did sneak a few glimpses without the glasses, as you’ll see in this clip, but they were split-second peeks. The “Trump blinded himself by staring at the eclipse” story is, I dare say, fake news:

WATCH: President Trump took a few glances at the #SolarEclipse2017 after taking off his protective glasses pic.twitter.com/espSHwMGwq

— NBC News (@NBCNews) August 21, 2017

He’ll be okay. I … think.

But wait — who’s that guy standing off to the side on the balcony with him? Could it be…?

Most adorable eclipse photo goes to… Jeff Sessions pic.twitter.com/9w4GtWRfnV

— Joe Perticone (@JoePerticone) August 21, 2017

Jeff Sessions hanging out with Trump at the White House? When did that rift get healed? Is it an eclipse miracle or did John Kelly pull the president aside and explain that it’s really weird and unseemly for him to be feuding publicly with his own handpicked AG? Either way, the stars have aligned and nationalist America has witnessed a harmonic convergence between the president and his populist attorney general.

Update: This reads like a pitch-perfect parody of Jared and Ivanka constantly spinning themselves as the voice of reason inside the White House after Trump does something questionable, but it appears to be legit:

Per sources: Ivanka/Jared among those pushing Trump to keep protective glasses on during eclipse Monday, "disappointed" that he did not…

— Benjamin Landy (@Ben_Landy) August 21, 2017

Tooconservative posted on 2017-08-23 07:31:34   Reply   Private Reply


#19: Hondo68    To: Tooconservative (#18)

He thinks that he's pointing out Kim Jong Un's kamikaze nuke coming in out of the sun.

See, I told you that fat kid was dangerous!

Hondo68 posted on 2017-08-23 08:53:46   Reply   Private Reply


#20: Tooconservative    To: hondo68 (#19)

You are good with the pictorial riposte, I have to admit.

Tooconservative posted on 2017-08-23 11:52:16   Reply   Private Reply


#21: misterwhite    To: Tooconservative (#7)

I can't say overcautious because we shouldn't encourage anyone to ever stare directly at the sun.

Vulcans can.

We hear about Trump's father but not his mother. I say she's Vulcan, which is why Trump can look directly at the sun.

misterwhite posted on 2017-08-24 12:33:19   Reply   Private Reply