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Medicine Science

Aging Eyes Blamed For Seniors' Health Woes 149

Posted by timothy
from the posting-this-from-the-villages dept.
Hugh Pickens writes "Scientists have looked for explanations as to why certain conditions occur with age, among them memory loss, slower reaction time, insomnia and even depression looking at such suspects as high cholesterol, obesity, heart disease and an inactive lifestyle. Now Laurie Tarkan writes that as eyes age, less and less sunlight gets through the lens to reach key cells in the retina that regulate the body's circadian rhythm, its internal clock that rallies the body to tackle the day's demands in the morning and slows it down at night, allowing the body to rest and repair. 'Evolution has built this beautiful timekeeping mechanism, but the clock is not absolutely perfect and needs to be nudged every day,' says Dr. David Berson, whose lab at Brown University studies how the eye communicates with the brain. Dr. Patricia Turner, an ophthalmologist who with her husband, Dr. Martin Mainster has written extensively about the effects of the aging eye on health, estimate that by age 45, the photoreceptors of the average adult receive just 50 percent of the light needed to fully stimulate the circadian system, by age 55, it dips to 37 percent, and by age 75, to a mere 17 percent and recommend that people should make an effort to expose themselves to bright sunlight or bright indoor lighting when they cannot get outdoors and have installed skylights and extra fluorescent lights in their own offices to help offset the aging of their own eyes. 'In modern society, most of the time we live in a controlled environment under artificial lights, which are 1,000 to 10,000 times dimmer than sunlight and the wrong part of the spectrum,' says Turner. 'We believe the effect is huge and that it's just beginning to be recognized as a problem.'"
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Aging Eyes Blamed For Seniors' Health Woes

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  • Cataract Surgery (Score:5, Interesting)

    by wisebabo (638845) on Tuesday February 21, 2012 @01:23PM (#39113023) Journal

    I believe the article mentions that cataract surgery will fix this problem, allowing the full amount of light (in the correct part of the spectrum) back in. (In fact, as a recent slashdot story mentioned, it sometimes allows you to see in the UV!).

    I wonder if people will choose to have cataract surgery done even if they have no cataracts. My mom was recently evaluated for the surgery, evidently it's a (relatively) simple procedure; the patient goes home the same day and only has mild discomfort for a few days.

    Hi Carl!

  • by Maximum Prophet (716608) on Tuesday February 21, 2012 @01:26PM (#39113055)
    "Life expectancy of the blind is usually less than half that of someone with eyesight the same age."

    That's according to http://www.cureblindness.org/world-blindness/ [cureblindness.org] which probably includes lots of accidents which are non-health related deaths. (Wow, there's a concept. He's dead, but a *healthy* sort of dead.)
  • by MozeeToby (1163751) on Tuesday February 21, 2012 @01:30PM (#39113121)

    It wouldn't be a bad idea, but honestly if you had a problem you'd know it by now, take it from someone with a circadian rhythm disorder. During my bad spells I have every symptom of an 80 year old man; lack of concentration, poor memory, poor reaction time, moodiness and anger, physical exhaustion, and of course extreme drowsiness. And that's even if I manage to get a decent 6 hours of sleep, when your body is determined that it is time to sleep it does not appreciate being kept awake. You can push through it for a day or two, maybe a week with enough willpower, but 3 weeks into a stretch where your body thinks that 5AM to 1PM is the perfect time to sleep when family, work, and friends all think differently... well... yeah... you'd know if you had circadian rhythm problems.

  • by vlm (69642) on Tuesday February 21, 2012 @01:36PM (#39113195)

    So uh, do populations where it's sunny year round have a significantly smaller population of people with memory loss attributed to ageing?

    That alone proves its bogus. A simple trigonometric function of latitude should correlate strongly with age related problems. That strong correlation does exist for indoor lighting.

  • by Sevalecan (1070490) on Tuesday February 21, 2012 @01:40PM (#39113259)

    I actually have a circadian rhythm disorder myself. Between 2005 and 2010 my sleep 'schedule' would go around the clock fully over a period of every 1-2 weeks. So, part of the time I was up during only the night, sometimes in between, sometimes during normal parts of the day. I have a greater than 24-hour sleep cycle naturally it would seem. However, I've been maintaining a pretty normal schedule for 1.5 years now. I started using sublingual 2.5mg melatonin lozenges after my sister told me about them. It totally did the trick in my case.

    Of course, more relevant to the article, there are lamps you can also buy for bright light therapy. I actually just got myself one about 11 days ago. It can take up to a few weeks to have an effect, and I think I've finally started to feel a measurable effect over the past 3 days, but I'll see how it goes before I make a final determination. According to what I've read, it can help with circadian rhythm disorders, but I personally bought it for the antidepressant effect. Perhaps I'll be able to switch over to using only the light, which would be pretty neat. But I wouldn't complain if I still had to use melatonin.

  • by Anonymous Coward on Tuesday February 21, 2012 @01:47PM (#39113395)

    Is there any psychological correlation with this phenomena and the desire to move to the brighter sunnier states - like Arizona and Florida - when one hits 75?

  • by Sevalecan (1070490) on Tuesday February 21, 2012 @01:52PM (#39113473)

    I use the Nature's Way Sublingual Melatonin in the 2.5mg potency. You can order it on Amazon, [amazon.com] if you prefer. They also come in other forms where you just swallow them, but then you tend to have to take them a few hours before you go to bed, whereas you can take the lozenge closer or at the time you intend to go to sleep.

    Disclaimer: I'm no doctor of course, but I'm told it's perfectly safe. I actually know of 3 people other than myself that use it without issues. I've also heard that if you take much more than 2 mg it can lessen the effect, but I've had no issues with the 2.5 mg lozenges.

    Interesting tidbit: I just did the math. I used to sleep for 9.5-10 hours, and then was awake for 16. That would make my sleep cycle around 25.5-26 hours.

  • Re:Cataract Surgery (Score:2, Interesting)

    by Anonymous Coward on Tuesday February 21, 2012 @02:06PM (#39113673)

    My mom had cataract surgery done and was shocked at how much brighter the world was. While they were at it they fixed her vision so she only really needed reading glasses. She was used to wearing bifocals at all times. This totally screwed her up for about a year. Her vision was one way for 60+ years (well aside from the gradual changes over time) and suddenly was completely different. She actually hated it at the time. The plus side was that her seasonal depression went away. Now that she is used to the change it does not bother her and she is actually much happier.

  • by Phat_Tony (661117) on Tuesday February 21, 2012 @03:25PM (#39114635)
    Everybody in this thread - The natural 25-26 hour schedule is completely normal for most diurnal mammals. They've done research with humans giving them NO time queues for days, and it turns out EVERYBODY falls into a slightly over 24-hour schedule.

    The conclusion here is that our chemical engines are too imprecise for us to evolve a dead-on circadian cycle. So instead evolution gave us an unaided circadian cycle that's calibrated with a mean of about 25 hours, so that people with a naturally extremely short cycle are still just over 24 hours, and it goes up from there. Then we get a natural reset cue to adjust the cycle every day to keep it in sync with the world. The primary component of the reset signal is sunlight exposure in the morning. If you get up at a reasonable time (near or after sunrise) and GET OUTDOORS for about 15 minutes, then you will feel like going to bed at the right time to get enough sleep and want to get up at about the same time the next day. We and our ancestors spent tens of millions of years with no choice but to receive natural light in the morning, so it was a pretty good system before we evolved to live in our parent's basements and stare at little screens all day.

    I suffer big time from this - every day I want to stay up and get up about an hour or so later than I did the day before - but not if I'm spending much time outdoors, especially in the morning. When I'm backpacking, wholly cow do I just want to go to bed when it gets dark, and get up just after sunrise. If we spent the day exercising outdoors like evolution intended, we wouldn't have this problem... but good luck being able to/wanting to do that all the time. But if you just drag yourself out of bed and take a 15 minute walk outdoors, even if it's cloudy or right around sunrise, problem solved. It does get tricky if you have to be at work before sunrise. Or if you work night shift (which I did for about 2 years) you're just *'ed.

    I think the light exposure causes melanin production on about a 14 hour delay, making us want top go to sleep about 16 hours after exposure. This is why melanin supplements near bedtime are somewhat functional as a surrogate for actual light exposure in the morning.

    Or as an alternate solution, since the day gets longer by about 1.7 milliseconds per century, by my calculations you could just wait about 200 million years for the earth to get in sync with your natural clock.

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