Light switches wired wrongly

[SUNRAY]

It's not supposed to see one pencil as two pencils and, as far as I am concerned doesn't do that.

As I've said, one should not perceive two apparent pencils, so I can't really answer that.

...

That's a silly suggestion. We're talking about images of actual physical objects. If there are 1, 2, 20 or 200 physical pencils, what is perceived should be 1, 2, 20 or 200 pencils respectively

And I would also expect the brain to perceive the correct quantity of objects if focused on them.
During a zoom meeting last night I got 5 people to do the Dominance test but this time pressured them to concentrate on the distant object until they could only see one finger, 4 always saw 2 fingers or 2 objects as they refocussed. the 5th. had no difficulty making the result you expect to see but no real surprise as he has very different L/R prescription in his multiple glasses.

I'm not disputing eye dominance, but I still don't understand how 2 working eyes fails to include the second image. My own observations across about 20 people is 2 on here and one with very different eye correction , so about the same sort of ratio as south paws

 

[JohnW2]

And I would also expect the brain to perceive the correct quantity of objects if focused on them.

It does, unless there is something pretty wrong with eye(s), brain or the connections between them.

During a zoom meeting last night I got 5 people to do the Dominance test but this time pressured them to concentrate on the distant object until they could only see one finger, 4 always saw 2 fingers or 2 objects as they refocussed. the 5th. had no difficulty making the result you expect to see but no real surprise as he has very different L/R prescription in his multiple glasses.

I'm still confused. As I keep saying, there's nothing 'special' about what we are asking people to do and, in particular, nothing special about their finger. Hence, if they are seeing two fingers when they are focussed on something else, why are they not always seeing duplicated versions of everything in front of them on which their eyes are not focussed?

I'm not disputing eye dominance, but I still don't understand how 2 working eyes fails to include the second image.

What is perceived is just one single image.

I don't know whether you realise how complicated a job the brain has in converting information from the eyes to the single image which one perceives. The images focussed on the retinas by the eyes' lenses are inverted, both vertically and laterally. Information from the left hand halves of the (inverted) retinal images of both eyes (hence right-hand halves of the scene one is looking at) is sent to the left side of the brain, and, similarly, information from the right-hand halves of the retinal images (hence left-hand halves of the scene being looked at) going to the right side of the brain. The two sides of the brain then have to work together to convert that (inverted and 'chopped up') information into the single image that one perceives, that perceived single image being 'complete' (the two 'halves' combined), the right way up and the right way around, and taking into account the slight differences between information coming from the two eyes (due to 'parallax').

 

[EFLImpudence]

I'm still confused. As I keep saying, there's nothing 'special' about what we are asking people to do and, in particular, nothing special about their finger. Hence, if they are seeing two fingers when they are focussed on something else, why are they not always seeing duplicated versions of everything in front of them on which their eyes are not focussed?

I do if focussed on something close. How can that not be the case?

The area of focus is very small.

 

[Harry Bloomfield]

I'm not disputing eye dominance, but I still don't understand how 2 working eyes fails to include the second image. My own observations across about 20 people is 2 on here and one with very different eye correction , so about the same sort of ratio as south paws

It just has to be, you that is interpreting, and explaining the test wrongly, to those 20.

The only way I can see one finger (or pencil), as two images, is to bring my finger closer than 3" from my nose, then it suddenly clicks in and out of appearing as two images - no doubt, due to it not being normal to have to interpret something at such short range.

 

[JohnW2]

I do if focussed on something close. How can that not be the case? ... The area of focus is very small.

Yes, if one focusses on something very close, the depth of focus is also very small, but that's not what we're talking about - we're talking about a finger "at arm's length" and another object much further away than that..

In any event, if I focus on something very close (e.g. about 6 inches), everything else is just a general blur, not 'double' - what about you?

 

[JohnW2]

It just has to be, you that is interpreting, and explaining the test wrongly, to those 20.

Yes, that's the only explanation I can think of.

The only way I can see one finger (or pencil), as two images, is to bring my finger closer than 3" from my nose, then it suddenly clicks in and out of appearing as two images - no doubt, due to it not being normal to have to interpret something at such short range.

Same here, and that's the situation in which one is on (or beyond) the borderline of being "cross-eyed" - and is certainly not the situation I've been talking about.

As I've said, the test of eye dominance I've described has stood the test of time, for at least many decades, so those who "can't get it work" presumably must be 'doing something wrong'.

 

[EFLImpudence]

Yes, if one focusses on something very close, the depth of focus is also very small, but that's not what we're talking about - we're talking about a finger "at arm's length" and another object much further away than that..

Not sure what the 'depth' of focus is; the area of focussed objects is very small when looking at things.

That's what I was talking about. Obviously the farther away your 'finger' (or object) gets the distance difference of things gets relatively less.

In any event, if I focus on something very close (e.g. about 6 inches), everything else is just a general blur, not 'double' - what about you?

I get two lots of blurs - i.e. two transparent offset images.

If you look at something with your right eye and left eye closed and then you swap eyes, is you nose still on the left side of your field of view?

 

[JohnW2]

Not sure what the 'depth' of focus is;

Have you never been involved with, or interested in, photography? It's the range of distances over which things are reasonably in-focus - e.g. 5" to 7"

the area of focussed objects is very small when looking at things. ... That's what I was talking about.

I'm not sure what you mean by "the area of focussed objects". Is it 'depth of focus' (as defined above) or something else?

I get two lots of blurs - i.e. two transparent offset images.

For me, everything is so blurred that I'm not sure how many 'images' (well, how many objects in the one image) I'm seeing - but, as I said, we're talking about extreme situations well divorced from what I've been talking about.

If you look at something with your right eye and left eye closed and then you swap eyes, is you nose still on the left side of your field of view?

Of course not.

 

[EFLImpudence]

Have you never been involved with, or interested in, photography? It's the range of distances over which things are reasonably in-focus - e.g. 5" to 7"

Yes, but I don't know how that applies when you are looking at something particular.

I'm not sure what you mean by "the area of focussed objects". Is it 'depth of focus' (as defined above) or something else?

The area of your field of view which is focussed - i.e. not peripheral vision - it is very small.

For me, everything is so blurred that I'm not sure how many 'images' (well, how many objects in the one image) I'm seeing -

I wouldn't say what I see is especially blurred - just not in focus as when I am looking at them.

but, as I said, we're talking about extreme situations well divorced from what I've been talking about.

I haven't read it all.

Of course not.

Of course not - so do you see two noses (or two fingers when touching nose) when looking at distant objects?

 

[Harry Bloomfield]

I'm not sure what you mean by "the area of focussed objects". Is it 'depth of focus' (as defined above) or something else?

Which is dependent on the lens aperture. The smaller the aperture, the greater the depth of focus, the larger, the shorter the depth of focus.

Often, those who wear glasses, can struggle to read without, by deliberately narrowing the opening of the eyelids, making the aperture smaller.

 

[SUNRAY]

It just has to be, you that is interpreting, and explaining the test wrongly, to those 20.

Yes, that's the only explanation I can think of.

In that case please explain to me in EXACT/PRECISE DETAIL how to conduct the test as the instructions so far MUST BE FAULTY if I and the 20 I've relayed it to cant't make the test work as sofar described.

 

[JohnW2]

Yes, but I don't know how that applies when you are looking at something particular.

It means, for example, that if you are looking at (focussed on) 'something particular' which is 6 inches away, anything between, say, 5 and 7 inches away will be reasonably in-focus, but anything at other distances will be out-of-focus.

The area of your field of view which is focussed - i.e. not peripheral vision - it is very small.

I don't understand what you mean by 'area'. As far as focussing is concerned, all that matters is distance from the eye - if you are focussed on one object 6 inches from your eye, then any other objects 6 inches from your eye will also be in focus,even if they are distant from the centre of your field of vision. One can only really 'concentrate on' things one is looking directly at (i.e. in the centre of one's visual field, but they will nevertheless be 'in focus' if they are the same distance from the eye.

I wouldn't say what I see is especially blurred - just not in focus as when I am looking at them.

As far as I am concerned, 'not-in-focus' and 'blurred' are essentially the same thing. The only way I could try to determine 'how many fingers' there were in 'the blur' would be to 'look at' (i.e. focus on) my finger - and that, of course, would destroy the experiment.

Of course not - so do you see two noses (or two fingers when touching nose) when looking at distant objects?

One, of course, since that is how the brain interprets the information it receives in order to create the image that one perceives.

 

[JohnW2]

Which is dependent on the lens aperture. The smaller the aperture, the greater the depth of focus, the larger, the shorter the depth of focus. Often, those who wear glasses, can struggle to read without, by deliberately narrowing the opening of the eyelids, making the aperture smaller.

Exactly, and the depth of focus obviously becomes more critical when viewing very close things.

That's why our eyes have an "accommodation reflex", such that the pupil constricts (aperture becomes smaller, hence increasing depth of focus) when one looks at close objects. One of the most basic parts of a neurological examination of patient is to get them to focus on one's finger a couple of feet or so in front of there face and then to 'follow' one's finger as one moves it progressively closer to their face/eyes. In the absence of a neurological problem,their pupil will get progressively smaller as one's finger gets closer to their face/eyes, and this is called the 'accommodation reflex'.

 

[morqthana]

I've always done it so did my Dad, I can also play cricket either way, not that I've done that for a few years

Did you ever do the thing where you change from RH batting to LH in the middle of an over?

I believe that as long as you do it before the bowler starts his run-up it is within the rules. Doesn't half mess up the placing of the fielders though.

 

[EFLImpudence]

It means, for example, that if you are looking at (focussed on) 'something particular' which is 6 inches away, anything between, say, 5 and 7 inches away will be reasonably in-focus, but anything at other distances will be out-of-focus.

If you definitely know that is the case then I cannot argue - but it seems unlikely because that will not be what you are looking at - in fact behind what you are looking at?
Also that would seem to be a poor judge of distance accuracy.

I don't understand what you mean by 'area'. As far as focussing is concerned, all that matters is distance from the eye - if you are focussed on one object 6 inches from your eye, then any other objects 6 inches from your eye will also be in focus,even if they are distant from the centre of your field of vision.

Again - those things will not be what you are looking at so can hardly be 'in focus'.

One can only really 'concentrate on' things one is looking directly at (i.e. in the centre of one's visual field, but they will nevertheless be 'in focus' if they are the same distance from the eye.

But they will be at an angle so are they in focus?

As far as I am concerned, 'not-in-focus' and 'blurred' are essentially the same thing. The only way I could try to determine 'how many fingers' there were in 'the blur' would be to 'look at' (i.e. focus on) my finger - and that, of course, would destroy the experiment.

I meant while looking at a distant object how many fingers (or noses) are you aware of.
Can you not 'see' more than one blurred object at a time.?

You are hard work at times, John.
I managed to hold off until page 9.

One, of course, since that is how the brain interprets the information it receives in order to create the image that one perceives.