Posted on 12/21/2007 7:24:50 AM PST by Watershed
Popular culture is loaded with myths and half-truths. Most are harmless. But when doctors start believing medical myths, perhaps it's time to worry.
In the British Medical Journal this week, researchers looked into several common misconceptions, from the belief that a person should drink eight glasses of water per day to the notion that reading in low light ruins your eyesight.
"We got fired up about this because we knew that physicians accepted these beliefs and were passing this information along to their patients," said Dr. Aaron Carroll, assistant professor of pediatrics at the Indiana University School of Medicine. "And these beliefs are frequently cited in the popular media."
And so here they are, so that you can inform your doctor:
Myth: We use only 10 percent of our brains.
Fact: Physicians and comedians alike, including Jerry Seinfeld, love to cite this one. It's sometimes erroneously credited to Albert Einstein. But MRI scans, PET scans and other imaging studies show no dormant areas of the brain, and even viewing individual neurons or cells reveals no inactive areas, the new paper points out. Metabolic studies of how brain cells process chemicals show no nonfunctioning areas. The myth probably originated with self-improvement hucksters in the early 1900s who wanted to convince people that they had yet not reached their full potential, Carroll figures. It also doesn't jibe with the fact that our other organs run at full tilt.
(Excerpt) Read more at livescience.com ...
“See #4. Is the pupil dilating in low light the cause of reduced acuity?”
No, the pupil does not dilate enough in scotopic (dim light) conditions to cause blur except perhaps in very young children who have very large, still highly reactive pupils.
This was the inaccuracy I mentioned in my original post. In and of itself, reading in dim illumination will not elicit consequent distance blur. I think they are confusing the effects of early presbyopia (loss of near vision beginning in the early 40’s). For presbyopic patients, prolonged nearpoint activity in WHATEVER lighting condition will result in a slow refocus to full distance vision. This is due to a simple thickening, with resultant stiffening of the crystalline lens with age and is independent of lighting conditions, photopic or scotopic.
They have an apex?
No, just a poorly developed prefrontal cortex
and he STILL kicks dem/lib butts
and he STILL kicks dem/lib butts
Here’s the list:
1. We use only 10 percent of our brains.
2. You should drink at least eight glasses of water a day.
3. Fingernails and hair grow after death.
4. Shaved hair grows back faster, coarser and darker.
5. Reading in dim light ruins your eyesight.
6. Eating turkey makes you drowsy.
7. Mobile phones are dangerous in hospitals.
Oh, I wouldn't be too sure about that. I have a USB receiver attached to the notebook via a USB extension cord. Whenever I accidently place my mobile phone near or on the cable, and the phone receives a call, the computer's USB port fails immediately, and I'll have to perform a restart to get it working again. I'm sure the interference of the boosted signal, while receiving a call, is causing errors in the data flow through the cable. It's the same reason one hears a "buzz" whenever a mobile phone, on call, is placed near an earphone cord.
“OK Eyeguy, I hear an ad on the radio occasionally about some kind of treatment that will improve your eyesight and you will not have to wear glasses anymore. I have never made a note of the exact name because it sounds like an ad by a snake oil salesman. Is there something to this claim or am I just smarter than the average bear?”
You are referring to the “SeeClearly Method”.
For the MOST part, total hogwash. There are in fact, in several states currently, attorney general actions against these charlatans. Yes, you apparently are smarter than the average bear, because they have made millions from this scam.
Now, having said that, the principles of eye exercises to improve focusing flexibility, eye coordination and overall visual skills have firm, study-documented validity. This therapy is used most often in children with reading/learning difficulties, but now increasingly with adults with near focusing stamina problems, largely attributed to the pervasiveness of the desktop PC. The lie is that this bonafide Vision Therapy can be used to correct significant refractive errors.
I call BS on this one. That's no myth.
I have to explain away this one almost EVERY day.
Even the correction in the article is not entirely correct.
There is no permanent change in vision
however there is a clear loss of Visual Acuity in
low contrast environments
Measured by the Contrast Sensitivity Curve
“I would prefer reading in lower-light conditions, but not exactly dim. We cant all see well in the dark, but I dont like reading with bright lights.”
Do whatever is comfortable for you and you will be just fine.
You know how they say we only use 10 percent of our brains? I think we only use 10 percent of our hearts.
Actually it is a collective concept, the 10% refers to those of us who frequent FR, less the Trolls.
Does beer count, too?
“When In the Phillipines we were told that the finely embroderied linens and hand made lace were made by young women because by 30 they were no longer able to see well enought to work. Their eysight was permanently damaged by years of very close work in very poor lighting.”
By age 30, in everyone the accomodative (focusing) mechanism has slowed considerably from that of childhood. This is age-driven and again has nothing to do with lighting conditions. Many of us become MORE nearsighted because of prolonged nearpoint work in childhood, but that in MOST case would make the embroidery task EASIER, unless their nearsightedness progressed to a severe level in which case the focal point would be too proximal to be useful for handheld tasks.
Again, this would not have anything to do with lighting conditions.
I see they didn’t challenge the activity that causes hair to grow on your palms. It must be true!
My eye doc put some drops in my eye yesterday that afterwards made it impossible to read! The drive home through blurry city lights was an adventure I don’t want to repeat. What a miserable experience.
2. You should drink at least eight glasses of water a day.”
There is an undeniable health benefit to drinking tons of water every day.
It is called extra exercise in the form of walking to the can.
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