Light switches wired wrongly

[JohnW2]

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.

The test itself (involving closing eyes alternately) is actually irrelevant, since the seemingly anomalous situation you are describing arises before one gets that far!

The "precise detail" of the process prior to the actual test is incredibly simple, and has already been described several times ...

• Look at/focus on/concentrate on some 'distant' object (anything over a couple of metres or so away will do).
• Extend one arm straight in front of you with one finger 'sticking up'.
• Whilst still looking/focussing/concentrating on the distant object, move that finger so that it is seen (in a slightly ghost-like fashion, since it''s out of focus) in front of the distant object.​

That's it (prior to progressing to the 'actual test'). One should see just that one 'slightly ghost-like' finger, not two.

 

[pete01]

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.

Yes I used to do it at school, not really played loads of cricket since, maybe I missed my calling

 

[SUNRAY]

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"

In photograpy and videography it's depth of field

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

In photograpy and videography it's depth of field

 

[morqthana]

I definitely see two fingers.

And they are in the places where I see one finger when I close one eye, i.e. when I close an eye, neither finger moves, but one disappears.

So the expected test result is that with my dominant eye open I see my finger aligned with the distant object, and with the other eye open I see it displaced to one side. That all "works" as expected.

It's just that with both eyes open I see two fingers - one aligned, the other displaced.

 

[SUNRAY]

The test itself (involving closing eyes alternately) is actually irrelevant, since the seemingly anomalous situation you are describing arises before one gets that far!

The "precise detail" of the process prior to the actual test is incredibly simple, and has already been described several times ...

• Look at/focus on/concentrate on some 'distant' object (anything over a couple of metres or so away will do).​

• Extend one arm straight in front of you with one finger 'sticking up'.​

• Whilst still looking/focussing/concentrating on the distant object, move that finger so that it is seen (in a slightly ghost-like fashion, since it''s out of focus) in front of the distant object.​

In that case I call bullshit as it is totally impossible for me to focus on a distant object then insert an object at arms length and only see a single occurance of that object

That's it (prior to progressing to the 'actual test'). One should see just that one 'slightly ghost-like' finger, not two.

If I continue with this fictional test and alternately close one eye I see the occurance of a single closer object (per eye) in the positions of the pair of occurances I see with both eyes open.

 

[JohnW2]

If you definitely know that is the case then I cannot argue ...

It has to be the case in terms of 'focus', since it's just very basic Physics. We are talking simply about an ('adjustable') lens which focusses an (inverted) image of objects in front of it onto a 'screen' (the retina) behind it. For any configurations of the lens (size, shape, position etc.) everything at one particular distance in front of the lens will appear as an in-focus image on the retina

- but it seems unlikely because that will not be what you are looking at - in fact behind what you are looking at?

Quite - as I said, one cannot really 'appreciate' that the non-central things are in-focus without 'looking at them', in which case one would automatically re-focus anyway, even if they had not been in focus before one 'looked at them'!

However, none of this digression about 'focus' has really got much, if anything, to do with what we've been discussing.

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

See above. "In focus" is a fact of Physics, and has nothing to do with what one is, or is not, 'looking at' (nor anything to do with our discussion).

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

Again, see above.

I meant while looking at a distant object how many fingers (or noses) are you aware of.

One

Can you not 'see' more than one blurred object at a time.?

That obviously depends upon how blurred the object(s) is/are - but I am not seeing two, blurred or otherwise.

This all started because morqthana, and then Sunray, started describing experiences/observations which would suggest that something which has been a standard test of eye dominance for many decades 'cannot work' - but that really doesn't make any sense.

 

[EFLImpudence]

I definitely see two fingers.

So do I.

As I began - how could you not?

 

[Harry Bloomfield]

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

You are wrong there, John...

With your one finger 6" from your nose, if you look at a distant object, you will see two distinct versions of your finger, due to the eye's direction angles, becoming more parallel.

 

[JohnW2]

You are wrong there, John...

I can't be 'wrong', since I am simply reporting observed facts ... i.e. ....

With your one finger 6" from your nose, if you look at a distant object, you will see two distinct versions of your finger, due to the eye's direction angles, becoming more parallel.

... if I do that, I do not see two versions of my finger, and that remains the case even if my finger is 1" from my nose.

However, see what I will shortly be writing, in response to morqthana, which will probably move this discussion forwards a bit.

 

[Harry Bloomfield]

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'.

That, I didn't know about.

 

[SUNRAY]

However, none of this digression about 'focus' has really got much, if anything, to do with what we've been discussing.

See above. "In focus" is a fact of Physics, and has nothing to do with what one is, or is not, 'looking at' (nor anything to do with our discussion).

It has everything to do with it (as regards human binoccular vision), you are asking me to focus on a distant object, which means my lenses are hopefully adjusting to achieve that focus and additionally the eyeballs are hopefully directed such that their central fields of view are coincident on the target object.

Now for any object at a different distance (and to a lesser noticable extent off to one side at the same distance of the focal point); the central fields of view of the eyeballs are not coincident on the additional object. Therefore the additional object will be percieved to be either 2 objects or one object in 2 different places. This last sentence you cannot dispute as it is no different to what you have been penning all the way through this part of the thread.

 

[Harry Bloomfield]

... if I do that, I do not see two versions of my finger, and that remains the case even if my finger is 1" from my nose.

Well, I certainly do see two versions, and logically, what I would expect - unless I move my focus from the distant object, to my finger, then the two, become one.

I will refer you to your post #126 above, where you agree with my post - that you can see two fingers, when your eyes snap to focus on a more distant object.

 

[SUNRAY]

I'd have been tempted to eat peas off a knife just to wind him up...

My tip: use syrup or honey on the knife to stop them rolling off.

 

[EFLImpudence]

Well, I certainly do see two versions, and logically, what I would expect - unless I move my focus from the distant object, to my finger, then the two, become one.

...and the distant object(s) become two.

 

[Harry Bloomfield]

Now for any object at a different distance (and to a lesser noticable extent off to one side at the same distance of the focal point); the central fields of view of the eyeballs are not coincident on the additional object. Therefore the additional object will be percieved to be either 2 objects or in 2 different places. This last sentence you cannot dispute as it is no different to what you have been penning all the way through this part of the thread.

I agree with that, assuming the doubled object, is nearer, or further away, than the object you are focussed upon. If the distance from the viewer is similar, then only one version of the none focussed upon object will be seen