Don't look at the Sun!
Every time there is a solar eclipse you will find astronomers warning you to never look directly at the Sun. Even more importantly, you should not look at the Sun through a telescope unless you have a professional solar filter that covers the front of the telescope. Why?
The Sun is very bright and by focussing the light onto the back of your eye (the retina) with or without a telescope, you are putting a lot of energy (both optical light and infra-red) onto a tiny area. At some point in your life you may have tried to set paper on fire using a magnifying glass, so just think about that being done to the back of your eye. It isn't nice. Even more scarily is the fact that the retina of your eye does not have pain receptors, so you will not even feel the damage being done. It may not even become apparent until later.
A grape at the focus of a small telescope while looking at the Sun unprotected. CREDIT: Stuart/Megan
Not only do you blind yourself, but you may damage the optics of your telescope. So, remember folks, NEVER LOOK DIRECTLY AT THE SUN. If you want to observe the Sun, check out the SOHO website or find someone with a solar telescope. You have been warned.
Comments: Don't look at the Sun!
"Not only do you blind yourself, but you may damage the optics of your telescope."
You're telling me, that eyepiece still smells of burnt sugar!
Seriously, the heat could destroy coatings on your eyepieces and cause lenses to crack. If you ever buy a telescope that comes with an eyepiece-mounted solar filter, throw it away as it could well destroy your vision if you use it. They may reduce the light in the optical part of the spectrum so that the Sun appears dark, but they generally still let through infra-red light which will cook your eyeball very quickly.
Posted by Megan on Friday 30th Sep 2005 (20:35 UTC)
Hey Stuart, you made the bad astronomy blog! There is a very lively discussion going on over there.
I will now use this article in my standard warnings when discussing solar observation.
I must admit that when I first started out, I used the eyepiece filter that came with my chinese refractor. After reading a few articles in astronomy magazines, I rapidly changed to eyepiece projection. WHich has the added advantage that many people can watch with you. It was a hit for the transit of Venus.
Posted by Ian Musgrave on Thursday 06th Oct 2005 (22:09 UTC)
I know! I wondered what was happening to my weblogs as the number of readers suddenly increased by a factor of about 150 since this morning. Everyone seems very shy though.
Posted by Stuart on Thursday 06th Oct 2005 (22:26 UTC)
I came over from Bad Astronomy. I'm very impressed by your experiment, but sorry about the eyepiece of your telescope. The price one must pay for scientific endeavour!
Posted by Beche-la-mer on Friday 07th Oct 2005 (03:56 UTC)
I guess you have never played with a magnifying glass and ants. *pop* *sizzle*.
Found by way of j-walkblog. I will be back. And I'm not shy.
Posted by Bret on Friday 07th Oct 2005 (16:14 UTC)
I also came over from Bad Astronomy. Pictures are worth a thousand words...so your video is at least a novella! That was wicked.
Posted by Ron on Friday 07th Oct 2005 (19:23 UTC)
Very interesting site. Increased traffic could also be FireFox's Stumble! Bar. That is how I found the site.
Posted by Jim Davis on Saturday 08th Oct 2005 (01:55 UTC)
I'm glad you all enjoyed the video clip. Thanks for saying hi.
Posted by Stuart on Monday 10th Oct 2005 (11:31 UTC)
That was a cool video! I have never looked directly at the sun with or without a telescope. And thanks to you i never will. I already have bad vison and i dont want it to be any worse!
thanks!!!!!!!!!!
Posted by Alex V. on Friday 30th Dec 2005 (19:42 UTC)
cool video!! im never looking at sun now. thanks for warning me Stuart!!!!!!!! i dont want to hurt my eyes!!!
Posted by avery on Friday 30th Dec 2005 (19:48 UTC)
If you have never looked directly at the sun,you have obviously never driven down a road when the sun is low in the sky.You can't look away,or you could have an accident
The reason it is dangerous during an eclipse is because your eye responds to the average light level ,which is low,& opens its aperture wide.the very narrow but intense light from the small part of the sun which is visible can freely reach the eyes internals
Posted by Bryan Wheeler on Saturday 28th Jan 2006 (14:41 UTC)
so your saying by looking at the sun you can go blind for ever?
E-mail me back
Posted by Andrew on Wednesday 13th Sep 2006 (14:53 UTC)
Andrew, what I'm saying is that looking at the Sun directly is dangerous to your eyeballs. Looking at it though a pair of binoculars or a telescope is even more dangerous.
Posted by Stuart on Thursday 14th Sep 2006 (16:59 UTC)
how dangerous is it tho out of 1 out of 10
Posted by Andrew on Friday 15th Sep 2006 (23:13 UTC)
never ever ever! look directly at the sun and i tell you this from experience. i have looked directly at the sun and now my vision is distorted. i cant see numbers very well anymore and i will never be able to see a straight line again; it will always have a bulge in it. when i close my eyes i can actually see the hole that i burned into the retinas of my eyes by staring at the sun so never under any circumstance look directly into the sun.
Posted by Faith L. on Saturday 16th Sep 2006 (00:53 UTC)
my god and you where looking at the sun for 5 or 10 minits?
i am geting a telescope soon i hope so i am just trying to find out all i can about it
but wat if its not a sunny day?
Posted by Andrew on Sunday 17th Sep 2006 (13:56 UTC)
Andrew, I'll echo Faith's comments that you should do your best not to stare at the Sun. You should certainly not look at it through a telescope unless it is a proper solar telescope with good quality filters on the front to reduce the amount of light going into it. The reason it is dangerous is that the Sun is VERY bright and so much light falling on the back of your eye is very likely to damage the sensitive cells in it.
Generally, if you are getting a normal telescope you will not be looking at the sky during the day so it isn't too much of an issue. Of course there are some occassions when you would want to use a telescope during the day but I suspect those will be sunny days (you don't see much that is astronomical when it is cloudy!). If you do observe during the day, just make sure that you steer well clear of the Sun.
Posted by Stuart on Sunday 17th Sep 2006 (15:09 UTC)
no dont ever look directly at the sun, I did it when i was younger and i went deaf.
Posted by david on Wednesday 08th Nov 2006 (16:29 UTC)
im realy worried about myself. i have an observitory OCD which makes me want to look at things and igzamine them. im worried that i might be overpowered by the sensation and start looking at the sun directly, even using the special methods to protect your eyes wont work cos my complex mind will just say "but what would it look like directly?" i have poor vision now possibly from excessive use of the computer and dont wish to damage my eyes further, i may have climpsed the sun up to 20 times since i was born =O
Posted by jamie on Sunday 12th Nov 2006 (20:26 UTC)
Jamie, try not to worry too much. If you do happen to glance at the Sun with your own eyes you should look away again as quickly as you can and blink a few times. (If there are any optometrists out there reading this they may be able to add some better advice here).
Of course, a much bigger problem would be looking at the Sun with some kind of telescope/binoculars. The best thing to do in that case is never to put a telescope in a situation where you can accidentally look at the Sun through it.
Posted by Stuart on Sunday 12th Nov 2006 (23:26 UTC)
ok, i was also wondering if this only aplys to the sun? i have powerfull disco lights in my room as my regular lighting, and i wasnt sure if this could do any damage. any advice please? thanks for the tips stuart, i tend to find that glimpsing the sun is a common accident, aspecially when the sun is dim and i dont realys its there when looking up. usually when its bright my light sensetive eyes make it impossible to see properly so i couldnt look at the sun anyway :P
i also heard that sun glasses that dont have the national safety mark are actually even worse for the eyes because they make the pupils bigger to let in more light, but dont protect from UV rays courses more damage =\
Posted by jamie on Wednesday 15th Nov 2006 (19:16 UTC)
on a cloudy? hmmmm...well i'll tell you that my uncle and i watched a partial eclipse of the sun on dec 25, 2000 (i think it was 2000) and we saw the whole thing through the clouds perfectly and even took some excellent pictures all through the clouds. on that day the clouds were just thick enough so that we could see the eclipse without the glare and just thin enough so the we could see every detail of the eclipse. it was awesome! however if you were to look at the sun through a telescope you would definitely do terrible damage to your eyes because its heat and light are magnified many times so whatever you do please please please dont use a telescope to look at the sun.
Posted by Faith L. on Friday 17th Nov 2006 (22:05 UTC)
lol that should be "on a cloudy day?"
Posted by Faith L. on Friday 17th Nov 2006 (22:07 UTC)
is it possible to look directly at the sun??? for more than 5 seconds???
Posted by benn9 on Sunday 26th Nov 2006 (23:57 UTC)
Benn9, it is possible but you will most likely do serious damage to your eyes. I would STRONGLY recommend that you didn't look at the Sun for any length of time.
Posted by Stuart on Monday 27th Nov 2006 (09:15 UTC)
i have hade eye problem for a few years ..when i look at writing the bit in the middle i cant see so if the word i was looking at was qwerty all i see is qwe ty..i have had tests they caNT FIND ANYTHING UP WITH THEM .I HAVE BEEN LOOKING ON THE NET FOR SIMPTOMS ..I AM 100% SURE ITS BEEN THE SUN .ARE THEY any treament for it
Posted by john on Tuesday 05th Dec 2006 (17:24 UTC)
John, this isn't the right place to ask for medical advice. If I were you I would contact an optometrist or opthalmologist and perhaps check out the Royal National Institute for the Blind's pages on low vision.
Posted by Stuart on Wednesday 06th Dec 2006 (09:52 UTC)
I should be blind according to this then.
I looked directly into the Sun today for more then an hour. I've spent as many as 3 hours in a row looking directly into the Sun. I've been looking every chance I can for the last 13 years.
I've looked into the Sun from a very young age.
I'm 49 now and getting a little far sighted but no noticable damage from looking into the sun.
I don't reccomend it if you think it will blind you. What you believe come into existance.
But like smoking cigerets, not everyone gets cancer from it.
Oh don't look.
I don't mean to sound like I'm saying to do it.
But I can. Want witnesses? I Got them. Lots
Peace
JE Moses
Posted by Jesus on Wednesday 13th Dec 2006 (07:33 UTC)
Jesus, I really don't believe that your statement is factually correct. However, even if I was to assume that it was, I think that it is very dangerous to make such statements. Despite your claim that you "don't mean to sound like I'm saying to do it" that is certainly what it will encourage. I do not understand what you wish to accomplish by this.
The analogy with cigarettes doesn't really work. Smoking gives you a statistical chance that you could damage a cell in such a way that it reproduces uncontrollably (i.e. cancer). However, allowing large amounts of sunlight direct into your eyes for some time will raise the temperature at the back of your eye. Heating up cells to high temperatures is a very sure way to kill them.
I have a final question. Why would you spend so long looking directly at the Sun over many years?
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Posted by Gariel on Monday 15th Jan 2007 (19:55 UTC)
My son was at school, during break time he decided to stare at the sun for 2 minutes. When he got back home he was watching tv and he kept saying there was something wrong with the colour, he kept seeing pink, then hour later more colours! will this have a long term damage on his eyes?
Posted by marie on Tuesday 23rd Jan 2007 (17:06 UTC)
I would seek medical advice if I were you. It will not have done his eyesight any good and it may have caused long term damage. You should take him to an optician for an eye examination. I hope he turns out to OK.
Posted by Stuart on Tuesday 23rd Jan 2007 (18:54 UTC)
Ever since I learned the dangers of looking at the sun, I have done my best to avoid it over the years. I am OCD so you can imagine how careful I have tried to be. However, playing baseball there were times that I had to stare directly into the sun many times in order to catch pop flys. Today, I walked out without my sun glasses. I came up to a traffic light and had no choice but to look directly into the sun in order to see when the light turned green. The sun was directly behind the signal so I literally had to look directly into it to see when I could go. I am freaking out because I probably looked right at it for about 2 seconds straight. It was so bright that I quickly looked away each time that I glanced up at it. I am worrying myself sick that I may have permaently damaged my eyes. My eyes seem to be working though as of now. Could someone tell me if I should worry about this? If it had done serious damage, would I already know it or could it show up at a later time?
Posted by Glen on Wednesday 07th Feb 2007 (01:08 UTC)
Glen, as far as I know it can take hours to a day or two to see the effects of damage from looking at the Sun. If you are worried, go see an optician or other eye specialist.
Posted by Stuart on Wednesday 07th Feb 2007 (09:50 UTC)
I've already watch directly the sun. The sky was clear, I looked at the sun directly for at least 2 minutes. I didn't feel any pain, and over a year later I don't notice any change in my vision, it is still as perfect as it was. But I don't recommend you attempting this. ( at the moment I was in a very conscious state of mind, and I believed that if I was to look at the sun it would not impair my vision ; seems I was right though )
Posted by Philippe on Monday 19th Feb 2007 (07:30 UTC)
Philippe, out of interest, where was the Sun in the sky (how high above the horizon) at the time?
Posted by Stuart on Monday 19th Feb 2007 (07:48 UTC)
Put your head 45 degrees backward and look straight. That's approximately where the sun was. Not absolutely sure though... But I can tell it was very very bright in the eyes.
Posted by Philippe on Monday 19th Feb 2007 (08:43 UTC)
YOU WEIRD BUT ..................
Posted by corinne on Tuesday 20th Feb 2007 (15:49 UTC)
I DIDN'T REALLY READ IT BUT THE COMMENTS SOUND INTERESTING.
Posted by COZZY on Tuesday 20th Feb 2007 (15:53 UTC)
OOGA
Posted by BOB on Wednesday 28th Feb 2007 (18:20 UTC)
WOW! this is pretty old. Anyway, nice blog. Im doing an assignment at school about looking at the sun and this has helped me to finish it. THANKS!!! :)
Posted by kieran on Tuesday 06th Mar 2007 (07:24 UTC)
dun dun dun
Posted by ??? on Tuesday 06th Mar 2007 (07:26 UTC)
i have desperatly been trying to find ways to look at the sun without hurting my eyes i dont want a picture or n e thing like that i want to look directly at it is there some type of tool i can use?
i was a a tripper for many years and no longer trip so i have permanent visuals now the sun gives off so many beutifull colors itself it is very hard for me not to look right at at and my girlfriend catches me staring at it and smacks me on the back of the head i cant help it there must be some way to see it without the harmful rays hurting my eyes someone please reply
Posted by scott on Monday 14th May 2007 (16:44 UTC)
Scott, get yourself some eclipse viewing glasses. Make sure they have a CE mark (or equivalent) so that you know they are safe. If you have a lot more money to spend, buy yourself a solar telescope. Both of these methods let you look directly at the Sun but cut out a huge amount of the light to make it safe.
Posted by Stuart on Monday 14th May 2007 (17:13 UTC)
I remember looking at the sun for the briefest of moments when we had the best UK solar eclipse many years ago.
The pain at the time was not good, and I wished I had not done it.
PS If anyone wants a link exchange between our astronomy sites, then please contact me.
Posted by Daniel on Thursday 05th Jul 2007 (15:35 UTC)
the info was great it really helped me in my homework normally i would look at the sun but now i have been warned and thank you
Posted by saranyia on Monday 13th Aug 2007 (08:25 UTC)
the info was great it really helped me in my homework normally i would look at the sun but now i have been warned and thank you
Posted by saranyia on Monday 13th Aug 2007 (08:25 UTC)
Hello my good friends. Recently I have suffered many problems due to my cat being murdered, it was a tragic event and made me soooo upset lolz. One day I looked at the SOON and it gave me energy and I had the feeling that god had forgived me for my sins and given me this energy. OPleadse forgove my Inglish im amermerican.
Posted by Ash on Tuesday 11th Sep 2007 (14:31 UTC)
Hi, I drive alot around 6:30, 7:00 PM. I drive the same way every day (to get home) and every time I do it, the sun is always right in front of the car, next to stop lights, etc. I am really frightened about what this could be doing to my eyes. I am wearing a pair of pretty cheap sunglasses, but feel I need more protection. Please advise. thanks
I really am worried about this. email me, ajsellaroli@gmail.com
Posted by AJ on Friday 14th Sep 2007 (19:43 UTC)
AJ, the thing to do in this sort of situation is to limit the amount of light (optical and UV) getting to your eyes. The simplest thing to do is what I do and pull down the sun shade (the thing with the mirror on it attached to the roof over the drivers seat). You can angle that to block the sun but still see some of the road.
As the year progresses this should be less of a problem because the Sun will set at a different time and in a different place.
Posted by Stuart on Sunday 16th Sep 2007 (12:25 UTC)
HOW ABOUT IF ONE LOOKS DIRECTLY AT THE SUN FOR A FEW SECONDS, WITHOUT THE TELESCOPE,ONLY WITH YOUR BARE EYE.DOES ONE GO BLIND?
Posted by ADRIAN on Friday 04th Jan 2008 (04:13 UTC)
When Iâ™m a little child a have a weird hobby sometimes in the morning or at daylight I like to see a sun with my bare eyes without any filers and I like it a lot even some time my tears dropping a lot, because after several minutes you will be different colors like rainbow and itâ™s very interesting. Right now Iâ™m 35 and my eyes still ok without using any glasses.
Posted by yan on Monday 14th Apr 2008 (02:13 UTC)