conuly: (Default)
[personal profile] conuly
So, prior to the eclipse there were FAQs and news reports about people who didn't want to go out on the day of the eclipse - even before it started! - for fear that they'd go blind, or didn't want to walk their dog because the dog might go blind (not knowing not to look at the sky on eclipse day, of course) or not letting the kids out at all during recess because, you got it, they might freeze in place, stare at the sun, and go blind.

And then Trump looked at the sun without glasses. And everybody is throwing fits about what an idiot he is. I commented on one article that no, it's not likely you'll go blind if you just glance at the sun for a second*, and one person replied "but this isn't the sun, it's the eclipse!" like that's a winning argument. I mentioned to another, who claimed you couldn't see anything without the glasses until totality anyway that I'd been staring at the cloud cover impatiently before the peak, and when the clouds parted I'd gotten an unprotected glimpse of the sun and yes, I could see the bite of it - and that person went "Well, you do permanent damage at 20 seconds, so you might've been lucky". How long do they imagine it takes to see the sun when the clouds break and then look down again?

I think I've figured this out.

The rule is "You should not stare at the sun, even during an eclipse". This is a sensible rule that nobody has ever needed to tell anybody over the age of, say, six weeks. We don't stare at the sun. Even infants know better - if the sun shines in your eyes, you squint, put your hand up, and turn away. Aniamls are even smarter! No matter what happens, they don't need to be told.

But humans think we're cleverer than animals, and during an eclipse we sometimes break that rule and look at the sun because it's cool. And because the light seems dimmer, we can look longer. But it's not really dimmer - it's just as bright, it's just that some of it is blocked. So for the past year, we've had it drummed into our heads that you shouldn't look at the eclipse without glasses. Consequently, many people have internalized the rule as "You shouldn't stare at the sun, especially during an eclipse". But the sun isn't any more dangerous then. It's only our behavior that changes!

If you look for up to five seconds, you're probably fine, just like when you turn a corner and find yourself driving toward the sun. (Or look up at a flock of birds just as the clouds part and find the sun glaring in your eyes, or wake up with the sun in your eyes.) According to the only study on the subject, you're not likely to have visible damage unless you look for 15 seconds or longer... and even then, most patients improved with time.

So don't stare at the sun, but if you did catch a glimpse, whether on purpose or not, it's probably no more harmful than when you catch a glimpse of the sun on regular days.

(As for Trump, this was a dumb move, but not because of the potential eye damage. It was a dumb move because everybody and their dog, literally, knows better but he still did it on national TV. Doofus. And if he's getting any flak from it he probably blames the aide for calling attention to his behavior rather than his own foolish decision to do something everybody knows, from the very day they're born, not to do.)

* Turns out it was more like 30 seconds in his case, which is really way too long. Not that I give a fuck what that person does to his eyes.

Date: 2017-08-22 06:30 pm (UTC)
zhelana: (Default)
From: [personal profile] zhelana
We may wind up with our first disabled president in a week or so. :p

Date: 2017-08-22 06:33 pm (UTC)
zhelana: (Default)
From: [personal profile] zhelana

derp!

Date: 2017-08-22 06:46 pm (UTC)
jenett: Big and Little Dipper constellations on a blue watercolor background (Default)
From: [personal profile] jenett
Also JFK.

(My current job means I was at a fascinating workshop/hopefully larger project with a bunch of people from different disability orgs and collections last summer. The presidential library folks were fascinating. We also had Bush Sr's library because of the ADA)

Date: 2017-08-22 06:34 pm (UTC)
zhelana: (Default)
From: [personal profile] zhelana

huh didn't know that.

Date: 2017-08-22 09:29 pm (UTC)
serpentine: (Default)
From: [personal profile] serpentine
I think Andrew Jackson also counts due to an old war wound causing him trouble according to wikipedia (they also mention chronic headaches, so).

Date: 2017-08-23 12:47 am (UTC)
amaebi: black fox (Default)
From: [personal profile] amaebi
I had no idea!

Date: 2017-08-22 06:43 pm (UTC)
flexagon: (Default)
From: [personal profile] flexagon
Yeah, less than 5 seconds is essentially okay (eclipse or no).

More than 20 seconds is essentially KNOWN NOT OKAY, which makes Trump's 30 a rather compelling proof that he didn't do his research. What's the source on that 30 seconds, by the way?

Date: 2017-08-23 12:04 am (UTC)
kyrielle: Middle-aged woman in profile, black and white, looking left, with a scarf around her neck and a white background (Default)
From: [personal profile] kyrielle
I've seen a couple videos. I've seen him take sub-second glances without the glasses, and one that was maybe 1-2 seconds, but the only prolonged staring I saw was with the glasses. These are all short segments, so maybe there was a longer look I didn't find, but...I'd expect it to be the most-featured.

Date: 2017-08-22 06:43 pm (UTC)
sabotabby: (lolmarx)
From: [personal profile] sabotabby
Oh, for sure! When I was a little kid, I misunderstood and thought that if you went outside at all without eclipse glasses, you would immediately go permanently blind and I was terrified. I suspect a lot of people did not, as children, subsequently freak the fuck out and had to be calmed down by an adult patiently explaining why.

Trump doing it on TV is not funny because he's actually going to go blind, but because everyone was joking that he would, assuming, incorrectly, that no one would be so stupid as to look up at the sun during an eclipse with a million cameras around when they happened to be President of the United States. The fact that he did it will never fail to be hilarious.

Date: 2017-08-22 07:57 pm (UTC)
brokenallbroken: (Default)
From: [personal profile] brokenallbroken
assuming, incorrectly, that no one would be so stupid as to look up at the sun during an eclipse with a million cameras around when they happened to be President of the United States

Which I don't understand, because thus far he's certainly been stupid enough to do everything else most people know better than to do.

Date: 2017-08-22 08:01 pm (UTC)
sabotabby: (lolmarx)
From: [personal profile] sabotabby
It's true! And yet part of me sincerely believes that no one is that stupid, and is gobsmacked literally every time he does something stupid.

Date: 2017-08-22 08:09 pm (UTC)
brokenallbroken: (Default)
From: [personal profile] brokenallbroken
I can't tell if my lack of shock over his daily new idiocy is an adjustment to our new reality or a symptom of a depressive downswing.

Date: 2017-08-22 08:10 pm (UTC)
steorra: Jupiter's moon Europa (europa)
From: [personal profile] steorra
From what I've read it is actually more dangerous to look at the sun during an eclipse. Can't look up my source now, but the idea that your pupils open wider in the lower light level, and the surface of the sun is just as bright as normal, so you can get more light concentrated on a given area of retina.

Date: 2017-08-23 02:40 am (UTC)
steorra: Jupiter's moon Europa (europa)
From: [personal profile] steorra
Now that I'm home and on a computer, not my phone:

This is the article I was basing my information on. Discussion of eclipses shows up in several places, but probably most relevantly under the heading 'Statistical evidence'.

Date: 2017-08-22 08:35 pm (UTC)
author_by_night: (Default)
From: [personal profile] author_by_night
It's like since the beginning of time, both humans and eye covers have existed to protect animals who might accidentally look at the sun OH WAIT.

Date: 2017-08-22 11:59 pm (UTC)
kyrielle: Middle-aged woman in profile, black and white, looking left, with a scarf around her neck and a white background (Default)
From: [personal profile] kyrielle
Hah! I know not to look at the sun, I knew that short glances didn't cause damage (because all the examples you list!), but never knew how long was a problem.

Thank you, I have learned something useful and reassuring today. :)

Date: 2017-08-23 02:43 am (UTC)
shadowkat: (Default)
From: [personal profile] shadowkat
Linkage:

1. Why Eclipse Damages Eyes

2. No Seriously Don't Look at the Sun During an Eclipse

3. A Solar Eclipse Can Blind You from Space.com

4. NASA on why it is dangerous to look at a solar eclipse.

However, observing the Sun can be dangerous if you do not take the proper precautions. The solar radiation that reaches the surface of Earth ranges from ultraviolet (UV) radiation at wavelengths longer than 290 nm to radio waves in the meter range. The tissues in the eye transmit a substantial part of the radiation between 380 and 1400 nm to the light-sensitive retina at the back of the eye. While environmental exposure to UV radiation is known to contribute to the accelerated aging of the outer layers of the eye and the development of cataracts, the concern over improper viewing of the Sun during an eclipse is for the development of "eclipse blindness" or retinal burns.

Exposure of the retina to intense visible light causes damage to its light-sensitive rod and cone cells. The light triggers a series of complex chemical reactions within the cells which damages their ability to respond to a visual stimulus, and in extreme cases, can destroy them. The result is a loss of visual function which may be either temporary or permanent, depending on the severity of the damage. When a person looks repeatedly or for a long time at the Sun without proper protection for the eyes, this photochemical retinal damage may be accompanied by a thermal injury - the high level of visible and near-infrared radiation causes heating that literally cooks the exposed tissue. This thermal injury or photocoagulation destroys the rods and cones, creating a small blind area. The danger to vision is significant because photic retinal injuries occur without any feeling of pain (there are no pain receptors in the retina), and the visual effects do not occur for at least several hours after the damage is done [Pitts, 1993].

The only time that the Sun can be viewed safely with the naked eye is during a total eclipse, when the Moon completely covers the disk of the Sun. It is never safe to look at a partial or annular eclipse, or the partial phases of a total solar eclipse, without the proper equipment and techniques. Even when 99% of the Sun's surface (the photosphere) is obscured during the partial phases of a solar eclipse, the remaining crescent Sun is still intense enough to cause a retinal burn, even though illumination levels are comparable to twilight [Chou, 1981, 1996; Marsh, 1982]. Failure to use proper observing methods may result in permanent eye damage or severe visual loss. This can have important adverse effects on career choices and earning potential, since it has been shown that most individuals who sustain eclipse-related eye injuries are children and young adults [Penner and McNair, 1966; Chou and Krailo, 1981].


5. Donald Trump looks at eclipse without glasses. He doesn't look for that long, maybe several seconds. But you can got and count for yourself. He looks like someone might squint at the sun.

According to the links above...there's a bit of a disagreement, some state you are fine for a second or two, NASA seems to indicate that the UV is worse during an eclipse than otherwise or intensified. I honestly don't know. The information hasn't been clear or straightforward.

Date: 2017-08-23 02:39 pm (UTC)
shadowkat: (Default)
From: [personal profile] shadowkat

Well, that's not entirely true. They've done various studies. And various opthamalogists are rather concerned about it. And they'd be the experts.

Samuel Wong, MD, and colleagues from the Leicester Royal Infirmary in Leicester, England, studied 45 patients after they observed an August 1999 solar eclipse. Although none of the patients who looked directly at the eclipse was totally blinded, 40 of them experienced discomfort or had visual disturbances or changes within the eye. Only five patients had no evidence of eye damage.

Nevertheless, the damage done to the eye can be severe enough to affect daily activities, according to the study, published in the British medical journal The Lancet.

Media warnings of possible eye damage when viewing eclipses may have made the observers more cautious, researchers postulate, resulting in less visual impairment than might otherwise have taken place. But while the researchers praised the media for these public health warnings, other eye experts have different opinions.

http://www.webmd.com/eye-health/news/20010124/solar-eclipse-beware-glare#1

  1. After Eclipse Keep Eye on After Images, Optometrist Warns.

  2. Damaged eyes

Early observers of astronomy sometimes found out about solar retinopathy the hard way. Thomas Harriot, who observed sunspots in 1610 but did not publish his discovery, wrote in 1612 that after viewing the sun his "sight was dim for an hour." Oxford astronomer John Greaves was once quoted as saying that after sun observations, he saw afterimages that looked like a flock of crows in his vision. In the most famous case of all, Isaac Newton https://www.livescience.com/20296-isaac-newton.html tried looking at the sun in a mirror, essentially blinding himself for three days and experiencing afterimages for months.

Scientists don't have a good bead on the prevalence of eye damage after a solar eclipse https://www.livescience.com/59663-how-solar-eclipses-make-people-go-blind.html. In one study, conducted in 1999 after a solar eclipse visible in Europe, 45 patients with possible solar retinopathy showed up at an eye clinic in Leicester in the United Kingdom after viewing the eclipse. Forty were confirmed to have some sort of damage or symptoms of damage; five of those had visible changes in their retina.

Twenty of the patients reported eye pain, while another 20 reported problems with vision. Of the latter group, 12 reported that their sight had returned to normal seven months later, but four could still see the ghosts of the damage in their visual field, such as a crescent-shaped spot visible in dim light. [If the Sun Is 93 Million Miles Away, Why Can't We Look Directly at It? https://www.livescience.com/59699-solar-eclipse-eye-damage.html]

"Our series demonstrates that, contrary to popular belief, the majority of people with eclipse retinopathy are not totally blinded," the researchers wrote in 2001 in the journal The Lancet. However, they warned, earlier Are the horror stories, valid? (shrugs) When I was in the 6th grade, the teachers didn't let us to go and watch the eclipse, even with the pin-hole boxes, because they were terrified we'd all look at the sun and blind ourselves. And various opthamologists were posting warnings on the internet. Also, I had my first pair of eclipse glasses recalled by Amazon because they didn't meet the criteria and could cause blindness.

Granted it probably doesn't completely, or birds would fall from the sky. But when you look at it, you may concentrate on it more than a bright sun.

Better safe than sorry, unless of course, you don't care about your eyesight? ;-)

Date: 2017-08-24 12:47 pm (UTC)
shadowkat: (Default)
From: [personal profile] shadowkat

True. I had some anxiety about it. So am somewhat relieved to discover that looking at the sun through filtered lenses for less than a minute or even if I look at it directly for a second without filtered, I'm safe.

You are not wrong about the media traumatizing people over this. In my search for linkage, I found an article about a city in Australia panicking over the eclipse, due to misinformation:

That Time a City Scared Itself Silly Over a Total Solar Eclipse.

Date: 2017-08-23 06:29 am (UTC)
oloriel: (for delirium was once delight)
From: [personal profile] oloriel
We had a partial (very partial - the BBC aptly called it "see the sun smile") eclipse a few years back and people were in total hysterics about OMG PEOPLE ARE GOING TO GO BLIND. School children weren't allowed to do recess because they might be tempted to staaare at the sun. Officials went on record saying "Well hopefully it's going to be a cloudy day so nobody gets hurt". As if the eclipsing sun sent out super power killer rays rather than just being, well, a sun.

Back in 1999, when we actually got a total eclipse, we got these warnings too, but we were also encouraged to buy certified eclipse glasses or use the pinhole method in order to observe that spectacular event. We were told not to use our unprotected eyes, but above all we were warned not to use inadequate protection like ordinary sunglasses (yikes!), thermo blankets, CDs or blackened glass in order to look at the sun. I totally get that: These things might give you a false sense of security so you actually would look at the sun for too long. I mean, with your unprocted eye, you'll probably go FUCK! BRIGHT! and look away at once. But if you think "Yeah I'm safe" you're going to override that instinct. And THAT'S the actual problem. As long as people are aware of that, they should be fine.

IIRC, we were also told that during totality, it was actually to look at the sun directly (or through a camera lense for that matter), but only for that one minute so better use the glasses all the time. But who knows. The Trumpster might actually have been catching the one minute (or 30 seconds) in which it was safe to be stupid?

In the event of the 2014 (or 15? I forget) partial eclipse, the ironic thing was that you couldn't even see anything special without eclipse glasses. Coverage was genuinely so small that it looked perfectly normal, and there was absolutely zero temptation to look at the sun any more than usual. *sighs*

Sometimes I wonder whether the problem is that a lot of the 90s scientophobic ignoramuses are now grown-up and in charge. And either nobody takes the time to explain it properly, or the people who should do the explaining didn't understand it themselves...

Date: 2017-08-24 05:55 am (UTC)
oloriel: (for delirium was once delight)
From: [personal profile] oloriel
Ah, my bad! I would have assumed that anyone with the resources would have gone to some place in the corridor of totality, so I assumed that since he was there, DC would be in it. >_>

Well, you gotta give him credit for one thing, he is very consistent in his disregard for science...

(Except in the field of plastic surgery, I guess. Never mind.)

Date: 2017-08-24 05:51 pm (UTC)
oloriel: (for delirium was once delight)
From: [personal profile] oloriel
Well, since he risked staring at it, some form of interest seems to have happened? Just not enough to prepare in advance, I guess, but once it came around, it seems to have been irresistible.

(It's not a crime but... how can someone NOT be interested in a total eclipse of the sun?)

Date: 2017-08-23 03:12 pm (UTC)
sitonmyinterface: (Default)
From: [personal profile] sitonmyinterface
My body doesn't allow for even beyond a milisecond to gaze toward the sun. My eyes shut automatically and my head turns away. The fact that he was able to do 30 seconds blows my mind.

Date: 2017-08-24 04:26 pm (UTC)
novel_machinist: (Default)
From: [personal profile] novel_machinist
I work at a hospital

People put sunscreen in their eyes.

Date: 2017-08-28 05:49 pm (UTC)
novel_machinist: (Default)
From: [personal profile] novel_machinist
both. I sadly mean both.


but it upticked during the eclipse so people could look at it.

Date: 2017-08-22 09:53 pm (UTC)
From: [identity profile] elenbarathi.livejournal.com
People are morons, and science education in the public schools is pathetically inadequate. We knew this already.

True Fact: the Sun is the Sun, regardless of whether it's partly obscured by the Moon, and the ultraviolet radiation it emits is very bad for the retina. Staring at the Sun is never a good idea, even when it's setting in a smoke-haze that makes it look like a dull-red rubber ball, because those UV rays are still coming. Staring at the reflection of the Sun (eclipsing or not) in water is not a good idea either, because some of those UV rays also reflect.

Practically everybody's retinas take some sun-damage over time, just like practically everybody's skin takes damage. Less if one avoids exposure, of course, but on the other hand, the more one avoids exposure, the more vulnerable one is to a burn if one does get exposed. Our species is predominantly diurnal, and originally evolved in the sub-tropics, so our bodies do have some useful adaptations to bright sunlight: enough to get us through the normal brief span of our lives, at least. Nobody reaches 100 with the eyesight, hearing, or sense of taste and smell they had at 10, regardless of how carefully they avoided bright light, loud noise, artificial flavors and polluted air.

The thing that bemuses me: so many people seem to have no frickin' clue what the Sun or the Moon even are, besides bright things in the sky. Oh sure, they know the Sun is hot and huge; they know we landed on the Moon, but... that's about it.

LOL, out at the Wildlife Refuge, I spend a lot of time explaining how the tides work - as briefly and simply as possible, but (fortunately) with the aid of an excellent tide-chart that an alert five-year-old could understand. The Sun and Moon have gravity, which is essentially the Power of Suck. The suck pulls the water toward it. When the Sun and Moon ride either together or opposite each other, both their suck is combined in one direction, so it pulls the water more; hence higher and lower tides. When the Sun and Moon are crossways, their suck is also crossways, so it cancels out somewhat; hence smaller tides. Not getting into the orbital parameters* that mean big minus (really low) tides come by day in Summer, by night in Winter.

Any real scientist would fall about laughing to hear such a sketchy excuse for an explanation. I'm not a scientist; I'm just a docent, and a sketchy explanation is as much as my peeps will stand still for. "Good enough for government work!"

*[Nobody - believe me, nobody - wants to hear me Explain orbital parameters: it's one of my little-known Evil Aspie Super-powers. 18 years ago, I had people seriously threatening to packet-bomb me back to the Stone Age for my obstreperous remarks re the Counter-Earth (with three moons!) vs. the Physics Police.]

Here's something to brighten your day! *hugs*

Indigo Girls - Galileo
Edited Date: 2017-08-22 10:02 pm (UTC)

Date: 2017-08-24 01:01 am (UTC)
From: [identity profile] alessandriana.livejournal.com
I looked when it was very close to totality, just to see if the brightness had dropped any. It didn't seem to have, and I definitely couldn't see the bite taken out of it, as I flinched away immediately. Looking at it did seem to hurt, but that could just be my synesthesia acting up. No harm done except for a momentarily bright purple patch in my vision that faded after a few seconds.

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