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Followup: Ultraviolet Vision After Cataract Surgery

xmas2003 writes "Several months ago, I posted to Slashdot about being able to see ultraviolet light after cataract surgery. While a lot of the discussion whimsically discussed the best way for 'Captain UV' or 'UltraMan' to use this 'super-power,' there were some people who were skeptical or (incorrectly) said this is Tetrachromatic vision. I've subsequently done more testing using an Oriel Instruments MS257 Monochromator and was able to see color down to 350nm — below the usual ~400nm limit of the visual spectrum. It's also easily demonstrable with a pair of 400nm and 365nm UV flashlights. Some readers who also have UV vision commented this can be quite annoying at black-lit Disney Rides, Halloween Haunted Houses, etc. Fortunately for me, it's just an interesting oddity so far. Along those lines, some interesting related stories about using UV vision during World War II and Star Gazing. Finally, many/most people end up getting vision debilitating cataracts, so my experience having a Crystalens implanted after cataract surgery may be informative."

58 of 311 comments (clear)

  1. Cool by Anonymous Coward · · Score: 5, Funny

    Can you see through clothes?

    1. Re:Cool by iamhassi · · Score: 4, Interesting

      Can you see through clothes?

      Apparently not, and honestly I'm having a hard time figuring out what good having UV vision is. What can you do with it? In your last /. post you called it a "superpower". Is it? How is seeing UV "super"? You're not faster or stronger or can fly or move things with your mind or see in the dark, you just see a spectrum of light no one else can. It's like being able to spit 100 yards, what good would that be? In fact I'd think it would be annoying, now I'm seeing things other people aren't, so lights might bother me while everyone else thinks it's fine and I'm the only one having a problem.

      Actually that's a good question: since you see UV light, could you use a UV flashlight to walk around in what appears to be almost complete darkness but you see just fine with the UV flashlight? I suppose that would be cool, not sure how useful that would be but interesting anyway.

      --
      my karma will be here long after I'm gone
    2. Re:Cool by mcavic · · Score: 3, Informative

      idiot

      Be nice. In The World's Not Enough, Bond's x-ray glasses were blue, not red.

    3. Re:Cool by iamhassi · · Score: 4, Insightful

      Actually that's a good question: since you see UV light, could you use a UV flashlight to walk around in what appears to be almost complete darkness but you see just fine with the UV flashlight? I suppose that would be cool, not sure how useful that would be but interesting anyway.

      Answered my own question: half-way down this page he says he can see light from a 365nm UV flashlight that appears to have no light. So yes, he could light his entire house in 365nm UV light and "see" while everyone else would see pitch black.

      That would be neat, but some things that would appear as black to other people actually appear as violet to him. I would find that annoying, I guess technically he's now color blind, "the inability or decreased ability to see color, or perceive color differences, under lighting conditions when color vision is not normally impaired", since now he perceives some black colors as violet.

      Think I'll pass on this superpower.

      --
      my karma will be here long after I'm gone
    4. Re:Cool by fuzzfuzz · · Score: 3, Informative

      "the inability or decreased ability to see color, or perceive color differences, under lighting conditions when color vision is not normally impaired", since now he perceives some black colors as violet.

      Not quite. Black is not a color.

    5. Re:Cool by quarterbuck · · Score: 4, Funny

      That's because it relected all the Blue colors and let the red colors through

      --
      http://slashdot.org/submission/1062723/Cheap-mobile-data-plan?art_pos=2
    6. Re:Cool by T-Bone-T · · Score: 3, Interesting

      The problem is he is sometimes seeing violet where everywone else sees black. A black object is black because it is not reflecting the wavelengths you are trying to detect. If something is perceived to be black to everyone else and is referred to by its color, he may not know which object is being referred to because everyone else's black object is his violet object.

    7. Re:Cool by dgatwood · · Score: 5, Interesting

      Difficulty seeing in a high-UV environment would be the least of my worries. If I found myself suddenly able to see UV, I'd be more worried about the increased risk of getting cancer of the optic nerve.

      Because UV is generally considered to be moderately dangerous, I would argue that this is a design flaw in the replacement lenses, and an easily fixable flaw at that. Until the manufacturer realizes their mistake, you should always wear a pair of clear glasses or sunglasses with a UV-opaque coating (on the outside) and an anti-glare coating (on the inside) to reduce the risk of permanent damage to your eyes.

      --

      Check out my sci-fi/humor trilogy at PatriotsBooks.

    8. Re:Cool by yurtinus · · Score: 2

      Not a good analogy. This would be something like a note at say 25KHz - it's there, but most people can't hear it.

      --
      +1 Disagree
    9. Re:Cool by Tyler+Durden · · Score: 2

      I think this depends on whether you consider color to be the external phenomenon you are perceiving or the actual perception that phenomenon creates within you. If it's the latter then you can argue that even the absence of light has an associated color with it. What if your mind associated the absence of light with what you currently perceive as green, and "green" wavelength light as black?

      But then, do the blind see black?

      --
      Happy people make bad consumers.
    10. Re:Cool by Anonymous Coward · · Score: 2, Insightful

      Actually it all depends on whether we are talking pigment or light.

      If its light, White is a mix of ALL colors, and black is the absence of any of the colors.
      If its pigment then White is the absence of pigment, and Black is all pigments combined.

    11. Re:Cool by dgatwood · · Score: 3, Informative

      You're seeing it because it successfully passes through the artificial lens where previously it was either reflected, diffused, or absorbed by your body's natural lens.

      If the natural lens absorbed or reflected the UV, this means that your retina is receiving significantly more UV with the artificial lens.

      If the natural lens merely diffused the UV (which seems somewhat unlikely), then your retina is probably getting more UV than it did before (because some of it would have hit other parts of the eye), and is also getting more intense UV in certain spots than it did before, but less intense UV in other spots. IIRC, a shorter exposure time increases the risk of cancer even if the total exposure is the same.

      Either way, it's not good.

      --

      Check out my sci-fi/humor trilogy at PatriotsBooks.

    12. Re:Cool by treeves · · Score: 4, Funny

      Silly argument. If there is a crayon with the word printed on it, then it's a color.
      I like "burnt sienna".

      --
      ...the future crusty old bastards are already drinking the Kool-Aid.
    13. Re:Cool by Pharmboy · · Score: 2

      Black == 0w/cm2 between 700nm and 400nm. He is referring to now being able to see between 400nm and 350nm, which is a type of violet. Specifically, "ultra violet".

      It is possible to light a surface with only 400nm-350nm light. We make ultraviolet lamps, and we have one that produces ZERO visible light in the 700nm-400nm range. To you and I, they look black. To him, it would be as bright as a regular light, but the color would be even more violet than violet. So yes, he would be able to see what you and I would call "black".

      To be sure, we don't actually SELL this light, because it would confuse customers who couldn't tell if it was working or not. It is an engineering masterpiece, and a marketing nightmare. It does, however, make a most excellent analog for this situation :)

      --
      Tequila: It's not just for breakfast anymore!
    14. Re:Cool by Iskender · · Score: 2

      No, think you are very wrong on that. What is the point of UV blocking sunglasses then if our eye lens would block out UV light naturally?

      Because neither set of lenses blocks it perfectly. This is typical of filters.

      It's a lot like some lethally poisonous delicious mushrooms. The poison is unaffected by cooking, so you should soak the mushrooms in water first. After you've done that you should do it a second time. This process doesn't remove the poison - it only removes something like 90% (per soaking) of it IIRC. Then you eat the poisonous mushrooms, and they're delicious.

      In the same way the 10% (I just made up that number for the point) of UV that gets past your own lens is still bad. 1% or even less that gets past shades and your eye is much better. Shades are only needed occasionally because the difference in solar UV probably varies by several orders of magnitude.

  2. Can you read this? by Pirulo · · Score: 5, Funny



    If you can't read the line above. Then you don't have UV vision.

    1. Re:Can you read this? by AioKits · · Score: 4, Funny

      If you can't read the line above. Then you don't have UV vision.

      Be sure to drink your Ovaltine.
      Ovaltine? A crummy commercial? Son of a bitch!

      --
      "Quote me as saying I was mis-quoted." -Groucho Marx
    2. Re:Can you read this? by jank1887 · · Score: 5, Funny

      rickrolled again. well played sir.

    3. Re:Can you read this? by Defenestrar · · Score: 2

      In HTML that's: GGGGGG, right? (What, can't do septadecimal for the augmented minority)?

    4. Re:Can you read this? by jones_supa · · Score: 3, Funny

      Let me test: *******.

      Hmmm. It seems I still see my password after clicking Preview.

      Only applies for you. As you can see from the quote above, it's not shown to others.

  3. Come back... by Brannoncyll · · Score: 4, Informative

    ...when you have X-ray vision!

    Seriously though, as someone who has a hearing range beyond the standard I sympathise with people forced to endure irritating stimuli that noone else notices and hence cares about. I remember having to leave a bar once because the tube was going on their old television; the high pitched screech was like nails down a blackboard. My girlfriend thought I was mad.

    1. Re:Come back... by SJHillman · · Score: 4, Interesting

      Having hearing aids can be much the same, only its possible (but usually very inconvenient) to take them out. Since starting at a medical facility, I've had several instances of my hearing aids picking up incredibly high pitched noise to the point where I had to leave the building. No one else even noticed there was a noise, much less one that powerful.

    2. Re:Come back... by mehrotra.akash · · Score: 2

      You dont need to have beyond normal hearing range to be irritated
      You just need to be young
      My home router emits a crazy pitch when its under heavy load, my laptop does it when on idle for a long time and my CRT does it always, but its noticeable when the audio is muted. Some tubelights ,power adaptors and voltage transformers do it as well
      But its rarely audible to the 30+ year olds

    3. Re:Come back... by twotacocombo · · Score: 2

      I can hear pretty much any tube TV, good or bad. My friends parents constantly turn off the cable box but leave the TV on with a black screen. The power light stopped working ages ago, but I sure know when it's on, and have to go turn it off. It's a horrible sound that you almost feel more than you hear. And then there are those people who can't even hear the smoke detector low battery chirp. Sometimes I envy them...

    4. Re:Come back... by Maximum+Prophet · · Score: 4, Interesting

      Don't hearing aids have magnetic detectors to work with telephones better? If that's the case with your hearing aids, you might be detecting high frequency magnetics that other people won't be able to hear.

      --
      All ideas^H^H^H^H^Hprocesses in this post are Patent Pending. (as well as the process of patenting all postings)
    5. Re:Come back... by Mashiki · · Score: 4, Interesting

      I have tinnitus, and can hear the whine of tubed TV's, tubed radio's(I own one), power adapters, various tube lights, and all that over top of it. I'm in my mid 30's. Actually it aggravates my tinnitus to the point where I need to put in ear plugs so the *weeeeennnneeeeeeee* doesn't get any worse.

      Generally anything above what people consider "whisper quiet" I find loud. Probably has something to do with the head injury 14 years ago, but I had sensitive hearing when I was a kid, but it's only gotten more-so as I've gotten older. Though my neurologist can't find anything wrong, neither can any other specialist I've been to.

      --
      Om, nomnomnom...
    6. Re:Come back... by jeffmeden · · Score: 2

      I notice very annoying "Bloom" around blacklight UV sources (much like he described in his blag) that is only present when I am not wearing glasses; meaning the light registering is almost certainly UV. Does anyone give a shit? No. And this is with stock eyes (something a lot of people probably experience); I can't imagine how annoyingly worthless his "power" is if it is improved beyond that.

    7. Re:Come back... by Alioth · · Score: 2

      I'm almost 40, TVs with tubes are still easy to hear. At least in one ear (I tried out my ears kind of non-scientifically the other week with my signal generator set to sine wave and the 10kHz scale and a decent set of headphones, my left ear almost gets to 18kHz, my right ear struggles to get above 15 or so. I know some years ago both could get to almost 18)

    8. Re:Come back... by fruitbane · · Score: 2

      Is has to do with the magnetism. I work in a library, and we have magnetic gates that detect active Tattle Tape strips in our books. If I'm wearing earphones when I pass through the gates they give off a high-pitched whine due to the magnetic influence on the speakers.

    9. Re:Come back... by Charliemopps · · Score: 5, Interesting

      I had the same problem until I was in my mid-tweties. I could hear VERY high frequency sound. The ear doctors equipment tested me all the way up to the limit of his testing equipment. I could "hear" when the headlights were turned on in a car. I could hear radio towers when we drove by them. It was so high pitched it was more like I felt the noise than heard it, it was very hard for me to pin-point the source, it was not very "Directional"

      But then, some time when I was around the age of 23, I went to a Motorhead concert. It cured me. I couldn't hear AT ALL for 2 days after the show, but after the ringing finally subsided I had normal hearing. Thank you Lemmy.

    10. Re:Come back... by omnichad · · Score: 2

      Probably because a lot of glasses filter out UV light to protect your eyes.

    11. Re:Come back... by JigJag · · Score: 4, Interesting

      33 years-old here. After reading your post, I decided to retry the Mosquito test.
      In normal conditions, I can't hear it, but there is a trick to hear it if you want. The idea is to increase the pressure in your inner hear (akin to compressing when scuba-diving: you pinch your nose while blowing air through the nostrils). Then, I can hear it clearly.

      The opposite is true by the way. If you want to decrease your hearing (like when at a concert or riding a train/subway): under-compress the inner hear. Close your mouth and pinch your nose while taking in some air forcefully. Immediate and temporary noise reduction in the order of 15 to 20 decibels if done right. I even found a way to do it without pinching the nose. To reset, yawn.

      JigJag

      --
      "The hallmark of humanity is the ability to move beyond sensory inputs" - Mary Helen Immordino-Yang
    12. Re:Come back... by treeves · · Score: 2

      "...increase the pressure in your inner hear (akin to compressing when scuba-diving: you pinch your nose while blowing air through the nostrils)"

      Also called Valsalva maneuver.

      --
      ...the future crusty old bastards are already drinking the Kool-Aid.
    13. Re:Come back... by Killall+-9+Bash · · Score: 2

      No doubt the result of aural sex.

      --
      "Prediction: within 10 years, Windows will be a Linux distribution." Me, 7-6-2016
  4. human eye lenses are naturally yellow/brown by waterbear · · Score: 5, Interesting

    Seeing UV after cataract surgery proabbly isn't a 'tetrachromic' effect. Human eye lenses are naturally yellow at birth, browner as we get older, browner still and they start being called 'cataracts'. They filter out the UV at any age. So the retina never usually gets a chance to try out its UV-seeing ability using its basic trichromatic receptor kit.

    -wb-

    1. Re:human eye lenses are naturally yellow/brown by philpalm · · Score: 2

      Most digital viewfinders can see infrared signals. Flash a tv remote towards a viewing camera and you can see light flashing at you from the remote.

    2. Re:human eye lenses are naturally yellow/brown by pz · · Score: 3, Informative

      Moreover, any plastic or (especially) glass lens you wear in a pair of frames will filter some-to-most of the UV even if the lens isn't specifically marketed to do that. Regular old glass filters out about 80% of UV. For polycarbonate (a/k/a CR-39, the standard eyeglass lens material), blocks nearly all of UVC, most of UVB, but passes much of UVA (blocks about 60%). Polycarbonate is often coated or treated with a UV-opaque dye for lenses that are marketed as UV-blocking.

      Normally, the anterior anatomy of the eye, including the crystalline lens, blocks most of UVA, so having an artificial lens implanted and then not wearing glasses would make one sensitive to UVA, and possibly UVB. Given that it would be stimulating the S (short wavelength) pigments, it probably would look intensely blue, but I'd have to check the spectra of the L (long) and M (medium) pigments to be certain ... might just appear whiteish.

      --

      Put my fist through my alarm clock with its ding-dong death inside my ear. - The Blackjacks.
  5. Be a Bee! Add polarized contact lenses! by wisebabo · · Score: 4, Interesting

    I read somewhere (on the net of a million lies) that Bees (and other insects) can see polarized light. Then you can see flowers in a whole way (and maybe better find your way home).

    Or get circularly polarized contact lenses and see like a mantis shrimp!

  6. Did it remove ability at the "red" end ? by Anonymous Coward · · Score: 2, Interesting

    In other words, does your new ability simply "shift" frequencies ?

  7. Try Some Astronomy by Iskender · · Score: 5, Interesting

    The relatively bright star Adhara (Epsilon Canis Majoris) is actually the brightest star in the sky in UV light. Of course you don't have pure UV vision but rather just a bit more UV bias.

    However, since you seem to enjoy an experiment I suggest going somewhere where at least the brightest stars are visible, and comparing relative brightnesses between stars with a person with average vision.

    Some background and a chart for Adhara below. It's close to Sirius which in turn is easy to find by using the belt of Orion.
    http://stars.astro.illinois.edu/sow/adhara.html
    http://www.rocketmime.com/astronomy/fig/CanisMajor_wAdhara.gif

  8. Re:Be a Bee! Add polarized contact lenses! by RDW · · Score: 3, Interesting
  9. Curses! by flyingsquid · · Score: 4, Funny
    WHAT???? A man has come forward who can see into the ultraviolet?!!??? This cannot be!!!

    I, the evil mutant Darklight, am the only one with power over the ultraviolet spectrum. If another emerged with such powers, it would threaten my Ultimate Ultraviolet plot for world domination. I must alert my co-conspirators Nucleon and Cheetahface and see if they can learn more about this "xmas2003". A curious choice for a superhero name... the "x" suggests some affiliation with the X-men and yet when I sucked out Xavier's brain he revealed nothing of this mutant to me. It also implies some sort of holiday theme, which is simply baffling. Perhaps he wears an elf costume?

    Very well, xmas2003. I will play your game. We will find you, and then we shall see if your powers are real. If I find that you have been toying with me with false claims, then I will kill you quickly. And if I find that you have been telling the truth, then I will kill you... slowly.

    After taking out those precious, precious eyes of yours, of course. AHAHAHAHAHAHAHAAAAH!!!!

    -Darklight, Evil Mutant Overlord

  10. I don't know if I can "see" UV... by FFOMelchior · · Score: 2

    I've also had cataracts surgery, when I was a toddler. And I've always noticed that UV has bothered me and not other people, but I've never thought about if I "see" UV, or at least see it in a way that others can't. Sometimes it's enough to cause my eyes to spasm. (In fact, my aversion is so strong, while reading this summary my mind _imagined_ seeing UV light, and my eyes spasmed for a few seconds in reaction.) Anyway, now I'm wondering if anyone else has this sort of reaction.

    1. Re:I don't know if I can "see" UV... by Flaming+Troll+Shill · · Score: 2

      Maybe you just need to get out of (your parents') basement more often?




      I kid, I kid ...

  11. Quite the write-up by Lev13than · · Score: 5, Funny

    That was an amazingly detailed and quite interesting write up - I found the numerous close-up photos and descriptions quite informative. Based on your proclivity for detail I am very glad that you suffered from cataracts and not colorectal polyips.

    --
    When you have nothing left to burn you must set yourself on fire
  12. What about spider webs? by MickLinux · · Score: 2

    Do the webs of writing spiders look like flowers now?'

    --
    Correct Horse Battery Staple: 72 bits of entropy. Enter "Correct H" into google. When it generates the phrase, that's
  13. Is this a good thing, or bad thing? by buckeyeguy · · Score: 2

    Does this mean that for the affected patients, more UV is reaching their retinas than before? If so, how could that be a good thing? Seems like more damage would be on the way.

    --
    I'd have a personalized plate on my car, but "toxic bachelor" won't fit into 7 letters.
  14. My brother can see infrared by Anonymous Coward · · Score: 5, Interesting

    A few years back my brother (who was about 14 at the time) got a Wii and was having trouble getting the controller to work. I was troubleshooting with him over the phone and asked him if the sensor bar was plugged in and he responded "I think so, no wait it's not. The light's not on." I asked him what light? The only lights on the Wii sensor bar are the infrared lights. He said he knew that, but they weren't on. Apparently he can barely see infrared light. I did some tests with some remote controls that do not light up when pressing the buttons and would ask him to tell me when I press the button. Not very scientific I know, but it was enough for me to prove that he does indeed see something. He can see the lights on remote controls, night security cameras, and of course the Wii sensor bar. They all appear very faint, but over Christmas I got him some cheap toy night vision goggles which apparently use infrared LED's and it was bright enough in a very dark room to act as a flashlight for him.

  15. I don't think this is a good thing. by dohnut · · Score: 4, Informative

    UV light and even blue light are damaging to the retina and UV light is a major contributor to cataract formation. The replacement lens you get after surgery may not block UV light at all (currently some replacement lenses do offer UV & blue light protection).

    Cataract surgery patients are advised to avoid blue light therapy products and, obviously, direct sources of UV radiation. Of course, protecting your eyes from UV radiation is generally a good idea for everyone.

    As someone who has a has a Grandfather with AMD (age-related macular degeneration) and I myself have, according to a genetic test, factors that make it more likely that I too will experience AMD, I try to protect my eyes as much as possible from both UV and blue light.

    --
    Stupider like a fox! - H.S.
    1. Re:I don't think this is a good thing. by ClosedEyesSeeing · · Score: 2

      As someone who has a has a Grandfather with AMD (age-related macular degeneration) and I myself have, according to a genetic test, factors that make it more likely that I too will experience AMD, I try to protect my eyes as much as possible from both UV and blue light.

      Don't worry, it's not as bad as Intel makes it out to be.

  16. Re:Be a Bee! Add polarized contact lenses! by amicusNYCL · · Score: 4, Interesting

    That's weird, you mean not everyone sees that? When I put on my polarized shades in the car my window tinting has those little spots all over it (at least, as far as I can see). I just assumed that's the way it was for everyone.

    --
    "Our two-party system is like a bowl of shit looking at itself in a mirror." - Lewis Black
  17. My Father's Cataract Surgery by assertation · · Score: 2

    My father is in his mid 70s and had cataract surgery.

    Before the surgery, for years, he hardly read anything and he was the most tech phobic of computer phobes, never saying why.

    After the surgery he started reading books, I convinced him to get an iMac ( instead of Vista, this was a few years ago )and to take the Apple store's classes.

    Years later he has his own web sites and sends me email.

    You can keep your UV vision, I have a minor miracle of my own.

  18. "Normal" vision is very subjective by joneil · · Score: 4, Interesting

    As somebody who is colour blind and undergone some extensive testing for it, I've been told by several people that the "normal" range of human vision between 400nm to 700nm is more or less an average. Everyone is different, and just as some people can naturally run a mile in 6-7 minutes with little training while others would have trouble walking a mile in 20 minutes, it is the same with our vision. IMO, a more true statement would be that the "weighted average" of human vision is 400 to 700nm, but the extreme ranges *might* go anywhere from say 350, 360nm to perhaps 720 or 730 nm.

          For example, even without a yellowed cornea, some people may not see into the UV at all. There are also suggestions - would not go so far as to say a sound theory - that some well known artists from days past had, perhaps without ever knowing it, natural extended vision into either the UV or IR, or perhaps even both. Just as it is claimed that some famous musicians from the past had a naturally extended range of hearing.

          Another thing to be aware of is that, at least IMO, the medical profession as a whole really seems to have little interest in this area. Specific example, I am colour blind, but it is very poorly understood. Also, since childhood, I have been extremely sensitive to bright light, but my night vision is superb, and apparently above that of the average person. I cannot tell you how many specialists I have either called or visited over the years, but the response is generally "I don't know" or "well, just live it it". It almost seems to me that if you cannot treat it or fix it right away, and you aren't going to die from it, why bother with it. so I have a small fortune invested in prescription eyeglasses, and I wear them even on cloudy days. You get some weird looks, but you get used to it.

          As for "proof", I can understand dealing with skeptical people. In terms of my own night vision, I had trouble even convincing my wife when we were first married. I solved that one real quick one night camping. Walking from our campsite to the washrooms, I left the flashlight behind. I was able to find my way no problem, but my wife keep tripping over rocks or branches in the dark. Even holding her hand she keep tripping or bumping into things. She sure wasn't impressed, but she has never doubted me since. :)

    1. Re:"Normal" vision is very subjective by Spectre · · Score: 4, Interesting

      I cannot tell you how many specialists I have either called or visited over the years, but the response is generally "I don't know" or "well, just live it it". It almost seems to me that if you cannot treat it or fix it right away, and you aren't going to die from it, why bother with it.

      Call around, find some more specialists. One of the simplest and least expensive treatments for color blindness is to consistently wear a red contact lens on one eye (always the same eye) and a clear contact lens on the other. Even if you don't need contact lenses to correct a different vision problem. Sure, it looks a bit weird, but only people who right in front of you and look you in the eyes are going to notice. It doesn't take too long for the brain to adapt the difference in signals from the two eyes to provide a "color cue" that restores a lot of the capability for the typical red-green colorblind-afflicted individual.

      I don't know if there are similar treatments for other forms of color-blindness, but there likely is ... don't give up!

      --
      "Flame away, I wear asbestos underwear"
  19. Re:Be a Bee! Add polarized contact lenses! by WeirdAlchemy · · Score: 3, Informative

    I don't think that's the Haidinger's brush effect -- I believe what you are seeing in the car window is the variability in birefringence from the strain pattern caused by the process of toughening the glass.. From the article:

    The strain pattern resulting from tempering can be observed with polarized light or by using a pair of polarizing sun glasses.

  20. Cataract will fluoresce green by Walt+Dismal · · Score: 2

    I've found that a cataract is easily visible with a UV LED flashlight because the cataract fluoresces bright green. I do not recommend looking at the light very long however, because the UV will accelerate the protein cross-linking and worsen the cataract. And the glow will freak out some people; it looks unearthly.

    I got my cataracts, by the way, from working 12 to 16 hour deathmarches and staring at screens then going home and collapsing into bed without removing my extended-wear contact lenses. Too long a period of this abuse (at a start-up) cut oxygen to my corneas, this then affected the electrolyte balance in the lens cells, and triggered damage to the colloids that constitute the contents of these cells. This caused the crystalin protein molecules to begin cross-linking to form cataracts. Normally, these molecules are held apart by delicate electrostatic forces, but various factors will disrupt those and begin the spiral into dysfunction.

    I urge people who wear contact lenses and work long hours for weeks on end to make sure they do not sleep in their lenses, and that they take proper eye nutrition supplements. The problem is easy to avoid, and hell to pay once it happens.

    1. Re:Cataract will fluoresce green by Jay+L · · Score: 2

      I've been sleeping in my extended wear lenses as well, and I've worried I'm taking a theoretical risk. Were these modern disposable silicone hydrogels, or the older extended-wear kind? As I understand it, cataracts arose as a side effect of microbial keratitis, and the risks of a severe infection are lower with silicone hydrogels (as well as with disposables in general).

      What sort of eye nutrition do you recommend?

    2. Re:Cataract will fluoresce green by Walt+Dismal · · Score: 2

      Sleeping in any extended wear lenses cuts O2 to the cornea and puts the deeper lens tissue at risk. Even if you feel very comfortable, it has longterm effects apparently.

      Cataracts from microbial action may relate to side effects that reduce moisture on the surface of the eye and that might affect internal fluid balance, I'm not sure. But anything that reduces chance of microbial infection is good. Many people have terrible ocular hygiene practice and no concept of bacteriology or viruses. They do unsafe things quite a lot. Always washing hands before handling lenses does good. I see people moistening lenses with saliva which is one of the worst things one can do bacterially.

      Nutrition, anything with lutein, zeaxanthin, anti-oxidants is supposed to be good. One can get them either from drugstore supplements or dietary intake. I eat dark green vegs.