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165111.  Thu Apr 12, 2007 5:35 am Reply with quote

Well we know that if you wear glasses which make the world seem upside-down, your brain will compensate after a few days, before recompensating with a similar time-scale when the glasses are removed.

Maybe if you'd persevered with the non-glasses-wearing thang you wouldn't need to wear them for non-blackboard activities after all.

165634.  Fri Apr 13, 2007 6:44 am Reply with quote

A map of the inside of the eye:

The inside of the eye derives its orange color from a layer of pigment cells inside the retina. This layer of pigment—just one cell thick—absorbs light coming in and prevents it from scattering. The result is a crisper view. How much pigment a person has is variable and is determined mostly by genetics. Optometrists call lightly colored retinas “blondes,” but the blondest retinas belong to vision-poor albinos, who have no pigment in their retinas at all.

Sitting just above the pigment layer toward the eye’s interior are light-sensitive rod cells and color-sensitive cone cells. Molecules in these cells change shape when light hits them. The change is translated into an electrochemical signal that is picked up by nerve cells, which relay it to the brain.

While most rods are evenly dispersed throughout the retina, all of an eye’s 6 million or so color-sensitive cones are concentrated in a 1/7-inch bull’s-eye of color vision—the macula. The speck in the center of the bull’s-eye is the fovea, which is so cone-dense that it creates a dip in the otherwise smooth retinal surface. About 30,000 cones are clustered here, more than anywhere else in the eye.

Cone cells work hard, and when their waste products build up faster than the body can clear them, tiny yellow spots can form around the fovea. As a person ages, these plaques, along with leaky blood vessels, tend to interrupt normal rod and cone functioning. Known as macular degeneration, this is the leading cause of vision loss and blindness in older Americans.

A layer of nerve cells coats the innermost surface of the retina. All nerve paths meet at the optic nerve—the large white spot—which transmits data to the brain at a rate of 10 megabits per second. That’s about as fast as a computer Ethernet cable. The optic nerve, technically considered brain matter, is the only part of the central nervous system that can be photographed directly. But the lack of light-sensitive rods where it meets the retina creates a blind spot.


165665.  Fri Apr 13, 2007 7:52 am Reply with quote

More eye-tracking stuff here.

A new study has unexpectedly found that men are more likely than women to first look at faces rather than other parts of a nude body.

Sadly no pictures this time.

165684.  Fri Apr 13, 2007 8:23 am Reply with quote

All nerve paths meet at the optic nerve—the large white spot—which transmits data to the brain at a rate of 10 megabits per second. That’s about as fast as a computer Ethernet cable.

Just so's you know, it's been many years since ethernet cables have been as slow as 10Mb/s. These days they can easily carry 100Mb/s and most can even cope with gigabit/second data transfer rates.

Technology progresses rather faster than evolution :)

165704.  Fri Apr 13, 2007 9:12 am Reply with quote

The eye does a lot of its own processing too, without having to ask the brain. It's like having a really good graphics card:
The optic nerve contains 1.2 million nerve fibers. This number is low compared to the roughly 130 million receptors in the retina, and implies that substantial pre-processing takes place in the retina before the signals are sent to the brain through the optic nerve.

So the eye can send such 'rich' messages as 'I've seen a dark stripe on a light background moving left-to-right'.

165722.  Fri Apr 13, 2007 9:34 am Reply with quote

sitting too close to the telly doesn't do your eyes any harm.

Television isn't good for migranes.

A WOMAN in hospital with a severe migraine was forced to extend her stay - when a bedside TV hit her on the head.


Molly Cule
166003.  Sat Apr 14, 2007 7:55 am Reply with quote

The socket in the skull where the eye sits is called an orbit. The skin that surrounds the eye of a bird is called an orbit too.

Molly Cule
166022.  Sat Apr 14, 2007 8:44 am Reply with quote

Quizzing glasses were monocles on a stick; they were held to the eye with a handle. One was shown on the first cover of the New Yorker, the cover is reprinted every February

The painting is called Eustace Tilley ‘quizzes’ a butterfly.

Molly Cule
166023.  Sat Apr 14, 2007 8:45 am Reply with quote


Molly Cule
166369.  Sun Apr 15, 2007 3:30 pm Reply with quote

When asked a question a "normally organized" right-handed person looks (from your viewpoint, looking at them):

Up and to the Left
Indicates: Visually Constructed Images (Vc)
If you asked someone to "Imagine a purple buffalo", this would be the direction their eyes moved in while thinking about the question as they "Visually Constructed" a purple buffalo in their mind.

Up and to the Right
Indicates: Visually Remembered Images (Vr)
If you asked someone to "What color was the first house you lived in?", this would be the direction their eyes moved in while thinking about the question as they "Visually Remembered" the color of their childhood home.

To the Left
Indicates: Auditory Constructed (Ac)
If you asked someone to "Try and create the highest the sound of the pitch possible in your head", this would be the direction their eyes moved in while thinking about the question as they "Auditorily Constructed" this this sound that they have never heard of.

To the Right
Indicates: Auditory Remembered (Ar)
If you asked someone to "Remember what their mother's voice sounds like ", this would be the direction their eyes moved in while thinking about the question as they "Auditorily Remembered " this sound.

Down and to the Left
Indicates: Feeling / Kinesthetic (F)
If you asked someone to "Can you remember the smell of a campfire? ", this would be the direction their eyes moved in while thinking about the question as they used recalled a smell, feeling, or taste.

Down and To the Right
Indicates: Internal Dialog (Ai)
This is the direction of someone eyes as they "talk to themselves".

How this information is used to detect lies:

Example: Let's say your child ask's you for a cookie, and you ask them "well, what did your mother say?" As they reply "Mom said... yes." they look to the left. This would indicate a made up answer as their eyes are showing a "constructed image or sound. Looking to the right would indicated a "remembered" voice or image, and thus would be telling the truth.

*** Looking straight ahead or with eyes that are defocused/unmoving is also considered a sign of visual accessing.

*** A typical left-handed person would have the opposite meanings for their eye-directions.

*** As with other signs of lying, you should first establish and understand a persons base-behavior before concluding they are lying by the direction of their eyes.

*** Many critics believe the above is a bunch of bull***t. In my own experiments I have found these techniques to be more true than not. But, why not find out for yourself? Make up a list of questions that like the sample ones, and give them to your friends/family anyone who would be your guinea pig, observe their eye movements and record the results.

166373.  Sun Apr 15, 2007 4:01 pm Reply with quote

That's very good, but the source is a bit thin - somebody's blog. Is it for real, do you think?

166416.  Sun Apr 15, 2007 8:40 pm Reply with quote

This sounds like something my future son-in-law explained to me about learning styles. He's a primary school teacher, and did his MA dissertation about different learning styles, and one of the things in it involved watching the way children's eyes moved when various questions were asked, to help determine their individual learning style (visual, auditory, kinaesthetic or a mixture). I think if we dig a bit more we could probably back it up if we needed to.

166438.  Mon Apr 16, 2007 4:32 am Reply with quote

This is covered by kinesics (see post 164445). I know because I recently read a thriller all about it, and am therefore an expert! Whether it is true or not, it is certainly (in outline) an accepted truth.

Molly Cule
167269.  Wed Apr 18, 2007 7:53 am Reply with quote

Why did Pirates wear eyepatches?

There are a few theories to suggest that they wore them so one eye was adjusted to top deck and the other for darkness below deck. When they ran between the two they would just swap patches. This was more effective than allowing the eye time to adjust to on deck and below and important especially when time was scarce like in times of battle. This was tested out in Mythbusters; The test that they ran in an opthamologist's lab showed that an eye's rods (the dark-vision sensors) can take 45 minutes to fully adjust from bright light to dim. Thus having an eye that's covered by a dark patch eliminates that 45-minute delay.

This will be a tricky one to nail as patches are more of an aesthetic detail added in works of later fiction, appearing in 20th C illustrations rather than in period pieces from the age of piracy.

Atomic bomb pilots wear eye patches to protect their eyes from the blast, they are lead-lined patches.

Nuclear bomber pilots would protect one eye from the blast. Les Frazier, retired US Air Force Colonel, explains all…
When a nuclear weapon denotes, the heat is tremendous and the flash is blinding, even more so if it detonates under an overcast sky where the clouds would help to reflect the glare into the cockpit. Even the dull black paint of the instrument panel shroud would reflect enough heat and light to burn through clothing and cause permanent blindness. For that reason, we always looked for a hill to hide behind after releasing the bomb and before detonation. We also carried lead-lined eye patches to cover the dominant eye after releasing the weapon.

Molly Cule
167270.  Wed Apr 18, 2007 7:56 am Reply with quote

Similarly, pilots at one time would also do the same, when flying at night over brightly lit cities, so that one eye could look out, and the other would be adjusted for the dim lighting of the cockpit to read unlit instruments and maps. When flashlights with red bulbs, backlit instruments, and other modern instruments came along, that no longer was necessary, just as boats and ships evolving into being well lit made eye patches a thing of the past for most boating.

This is from wikipedia, there isn't much else about this on this internet but Flash was going to ask an expert friend about it. So this post is more of a reminder than anything else.


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