Well, I can't very well comment since you didn't say why you "needed them".
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swaro news (1 Viewer)
- Thread starter jan van daalen
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Myopia even then, youth is no guarantee that everything is perfect.
Conceptually, the prospect of replacing worn out body parts has appeal, the challenge is melding the replacements with the existing components.
Hopefully we will learn to grow the needed spare parts ourselves, rather like sharks grow replacement teeth
elkcub
Silicon Valley, California
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I'm reaching back into a very faulty memory here, but it is my recollection that your myopia can be dialed out by selecting the focal length of the implant lenses appropriately, so the replacement parts will work better than the OEM parts.
They will be colorless, so you will see the entire visible spectrum with no filtering of the short end by old, yellowed lenses. I noticed an enormous difference in that part. When I had only had one eye done, I could compare directly. The difference was quite stunning.
I really do recommend it.
Sorry if I have strayed off topic.
CharleyBird
Well-known member
Is any of this field-flattening distortion discernible when using the 12x42 NL?
ticl2184
Well-known member
Haven't tested the 12x42, but I saw it in both the 10 and 8x when I tested them in September 2020..
Cheers
Tim
brocknroller
porromaniac
I don't think it's about sample variation in optics but rather sample variation in people's perception of the "much fabled" Absam Ring.
The irony is that I'm the one who first coined the term "Absam Ring," and I have never seen it! At least not directly, only in photos. I have seen the not-so-fabled "Nippon Ring" (a term I also coined but that never caught on) in my Nikon 10x42 SE, which is similar, so I knew what it was when someone first described it on BF in the EL.
Henry documented the Absam Ring with his photos of the "mustache distortion" (a term he coined) on the ELs, so I trust that the ring is actually there. It represents the turning point where the optics' distortion goes from pincushion to AMD.
But like "rolling ball," a term I first coined on Cloudy Nights after buying 8x and 10x42 LX's, and "rolling bowl," which I first coined on BF after buying a Zen Ray ED, and chromatic aberration (don't blame me for that one
), people's perceptions vary greatly, so it doesn't surprise me that one person sees the Absam Ring and another doesn't any more than one sees RB or CA and another doesn't them the same binoculars.The brain's neuroplasticity is amazing. I would like to find out if like chickens, humans could adjust to an upside down world after having inverted prisms attached to their head for a week. Any volunteers?
willisoften
Well-known member
Newborns see the world upside down and back to front. The brain sorts that out in the first few weeks. There have been experiments done with mirror goggles and depending on the individual people do manage the reversed upside down view after a time. However, I don't know if they adapt or if the brain rights the image again.I would like to find out if like chickens, humans could adjust to an upside down world after having inverted prisms attached to their head for a week. Any volunteers?
brocknroller
porromaniac
That's a great example of neuroplasticity. A child’s brain is more "plastic," i.e., more capable of change and new learning than a typical adult brain, but even an adult brain can create new neuronal connections and even new neurons born from neuronal stem cells. So, my guess is that the brain corrects the image with people fitted with mirror goggles as it does with babies. Images are upside down when they hit the retina since our eye lenses flip images upside down just a glass lens would, but the brain is able to flip the image to make an right side up world. The only exception is when you become drunk, then you might find yourself "Dancing on the Ceiling."
elkcub
Silicon Valley, California
I'm not sure that I fully agree with this, so do you have a book or journal reference for it? I'm particularly interested in the statement: "Newborns see the world upside down and back to front." Here, I assume you mean newborn humans.
Thanks,
Ed
willisoften
Well-known member
I don't have a reference - other than Open University. (BBC2) with a title like "Using your vision is a learned activity".
I'm sure this was also taught in Biology at school. Admittedly memory is often the worst reference.
Yes I'm talking about human newborns.
New born zebras for instance achieve body awareness / orientation and coordination within minutes.
I'm sure this was also taught in Biology at school. Admittedly memory is often the worst reference.
Yes I'm talking about human newborns.
New born zebras for instance achieve body awareness / orientation and coordination within minutes.
John A Roberts
Well-known member
Googling 'inverted vision in newborns’ gives a variety of matches
The first article on the list that I got starts with:
'An image focused by the human eye on the retina is ALWAYS inverted: top for bottom; right for left. This was true at birth and continues throughout life’
(author's emphasis; it's from: https://www.woodhamseye.com/blog/at...yes-inverted-image-and-if-an-adult-would-wear ) *
And see an image from Quora
The both vertically inverted and laterally reversed image created by the eye, is like the image created by an astronomical telescope or a camera lens
(for those old enough to remember loading film into a camera, looking at the information on the rebate in relation to the developed image made the vertical inversion obvious; and anyone who used a TLR camera with a waist level finder, was immediately aware of the lateral reversal when attempting to frame a subject)
Contrast the above to a terrestrial telescope or a binocular, where a second inversion and reversal presents the image correctly orientated to the eye
For illustration, see an image from Swarovski of a telescopic sight (without the complication of prisms):
• the first part of the system brings the image to a focal point both inverted and reversed, as in the eye, then
• the second part of the system again inverts and reverses the image for correct viewing (the eyepiece group then magnifies the corrected image)
John
* the article mentions the experiment where spectacles were used to invert and reverse the normal vision of adults, and that within a few days they had adapted to the changes!
The first article on the list that I got starts with:
'An image focused by the human eye on the retina is ALWAYS inverted: top for bottom; right for left. This was true at birth and continues throughout life’
(author's emphasis; it's from: https://www.woodhamseye.com/blog/at...yes-inverted-image-and-if-an-adult-would-wear ) *
And see an image from Quora
The both vertically inverted and laterally reversed image created by the eye, is like the image created by an astronomical telescope or a camera lens
(for those old enough to remember loading film into a camera, looking at the information on the rebate in relation to the developed image made the vertical inversion obvious; and anyone who used a TLR camera with a waist level finder, was immediately aware of the lateral reversal when attempting to frame a subject)
Contrast the above to a terrestrial telescope or a binocular, where a second inversion and reversal presents the image correctly orientated to the eye
For illustration, see an image from Swarovski of a telescopic sight (without the complication of prisms):
• the first part of the system brings the image to a focal point both inverted and reversed, as in the eye, then
• the second part of the system again inverts and reverses the image for correct viewing (the eyepiece group then magnifies the corrected image)
John
* the article mentions the experiment where spectacles were used to invert and reverse the normal vision of adults, and that within a few days they had adapted to the changes!
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elkcub
Silicon Valley, California
Hi Will,
This area of visual perception has been studied extensively in the US and Europe by experimental psychologists dating well back into the 1800s. A commonly referenced publication (see below) that is worth reading was presented by Dr. George Stratton at the Third International Congress for Psychology, Munich, August, 1896. In the mid-20th Century, Ivo Kohler researched the field extensively, but unfortunately much of his work was written in German.
The reason I queried the origin of your statement: "Newborns see the world upside down and back to front. The brain sorts that out in the first few weeks," is that historically it has been a fundamental question in the area of developmental psychology as to how much learning is involved in an infant's visual perceptual processes. To my knowledge that issue has never been resolved.
If anyone is interested in a deeper understanding of the subject, I'd recommend a book edited by psychologist Charles S. Harris entitled "Visual Coding and Adaptability," 1980. It can be purchased from AbeBooks.com at a ridiculously low price.
The second attached article: "Visuomotor Adaptation to Displacing Prisms by Adult and Baby Barn Owls" makes several references to Harris' book, and might be of interest to those more interested in birds.
Ed
