Light switches wired wrongly

[JohnW2]

I'm seeing two fingers, all the way from arm's length, to touching my nose, providing I focus on the TV screen, at the far side of the room.

Ah! Is this perhaps, at very long last, a 'Eureka moment' in terms of my understanding of the problem that you all seem to be having with the test? Have you all perhaps been misunderstanding the test?

People undertaking the test are asked to hold up a finger at arm's length and "look at it" (with both eyes open) - which nearly everyone usually interprets (correctly!) as meaning focus on it. They are then asked to move that finger (whilst still 'looking at'/'focussed on' it) so that it lines up with some (somewhat out-of-focus) distant object. Finally (again, whilst still 'looking at'/'focussed on' their finger), they are asked to close each eye in turn and see whether or not the finger they are looking at seems to move in relation to the out-of-focus distant object.

At no point should they focus on the distant object. If they do, their finger will become out-of-focus and very probably will be 'seen double'.

Does this perhaps explain all the 'problems' of our previous discussion?

When I see two, the more defined image, seems to be that from my right eye, however recent eye tests, suggest my right eye is not as good as my left.

Under normal circumstances, "how good" an eye is (in terms of visual acuity) has got absolutely nothing to do with dominance. Most people are born with one eye being dominant and, other than in exceptional circumstances, that will remain unchanged for life, even if visual acuity in the dominant eye deteriorates to the extent of being 'much worse' than in the non-dominant eye. I suppose it's possible that, in the very long term, if vision in the dominant eye became very poor, dominance might switch to the other eye, but I somewhat doubt that, and certainly don't recall having heard it being suggested.

 

[SUNRAY]

Having had a lengthy discussion last night and posted my #209 I've read the whole thread again (just the eye test parts) and one of the things I had not so far mentioned is I am very aware of the difference between my eyes, both in terms of required prescription and brightness, as such I know I require a stronger left lens for close work and doing the dominance test more of the distant object is obscured with what I see with my left eye with both eyes open (but relative light levels can change this)

 

[JohnW2]

But I thought we'd basically rubbished it before as the stereoscopic/binocular vision we have makes it impossible to focus at 2 distances, and therefore see just one of each at those distances, at the same time.

See what I've just written to Harry.

Indeed, one cannot focus on two appreciably different distances at once - but it rather seems that most/alll of you may have been focussing on the wrong thing! For the test to work, you must at all times focus on your finger, never on the distant object - and that is how nealy everyone usually interprets an instruction to "look at your finger" .

 

[JohnW2]

Having had a lengthy discussion last night and posted my #209 I've read the whole thread again (just the eye test parts) and one of the things I had not so far mentioned is I am very aware of the difference between my eyes, both in terms of required prescription and brightness, as such I know I require a stronger left lens for close work and doing the dominance test more of the distant object is obscured with what I see with my left eye with both eyes open (but relative light levels can change this)

That may complicate things a little in your case, by somewhat frustrating the 'mechanism' of the test but, as I've just written, differences between eyes (in terms of acuity etc.) do not have any influence on dominance.

 

[EFLImpudence]

Mad a mistake.

 

[EFLImpudence]

If it helps:

People undertaking the test are asked to hold up a finger at arm's length and "look at it" (with both eyes open) - which nearly everyone usually interprets (correctly!) as meaning focus on it.

Ok.

They are then asked to move that finger (whilst still 'looking at'/'focussed on' it) so that it lines up with some (somewhat out-of-focus) distant object.

Which one? There are two of each distant object.

Finally (again, whilst still 'looking at'/'focussed on' their finger), they are asked to close each eye in turn and see whether or not the finger they are looking at seems to move in relation to the out-of-focus distant object.

To me, it looks more like the object moves from behind the finger to one side.
Which side being dependent on which of the two objects was first chosen.

At no point should they focus on the distant object. If they do, their finger will become out-of-focus and very probably will be 'seen double'.

It does.

Does this perhaps explain all the 'problems' of our previous discussion?

I don't know.

 

[JohnW2]

Which one? There are two of each distant object.

One doesn't really need to 'look at' or think about the distant object(s).

When I do the test, keeping my eye(s) focussed on my finger, when I close one of my eyes, then absolutely nothing changes, but if I close the other, my finger jumps significantly to the side, relative to all of the (somewhat out-of-focus) distant 'background' in general. Is that not the case for you?

 

[Harry Bloomfield]

Having had a lengthy discussion last night and posted my #209 I've read the whole thread again (just the eye test parts) and one of the things I had not so far mentioned is I am very aware of the difference between my eyes, both in terms of required prescription and brightness, as such I know I require a stronger left lens for close work and doing the dominance test more of the distant object is obscured with what I see with my left eye with both eyes open (but relative light levels can change this)

I'm lucky, both eyes are the same prescription, so I'm generally able to buy the cheap Poundland glasses, and throw them away when damaged- I'm quite tough on glasses, and often break them. I first began wearing them, when I noticed red LED warning lights, seemed to turn a blurred mush. I now tend to wear them all the time, except when outdoors. For driving, they prescribed a very low diopter, so my distance sight, is almost as good without, as with the glasses.

I can usually manage to read even the smallest text, on a screen, without glasses, with just a little narrowing of my eyes. The acuity of my eyes does seem to vary a great deal, some days I really struggle to focus on a laptop screen.

 

[SUNRAY]

Ah! Is this perhaps, at very long last, a 'Eureka moment' in terms of my understanding of the problem that you all seem to be having with the test? Have you all perhaps been misunderstanding the test?

People undertaking the test are asked to hold up a finger at arm's length and "look at it" (with both eyes open) - which nearly everyone usually interprets (correctly!) as meaning focus on it. They are then asked to move that finger (whilst still 'looking at'/'focussed on' it) so that it lines up with some (somewhat out-of-focus) distant object. Finally (again, whilst still 'looking at'/'focussed on' their finger), they are asked to close each eye in turn and see whether or not the finger they are looking at seems to move in relation to the out-of-focus distant object.

At no point should they focus on the distant object. If they do, their finger will become out-of-focus and very probably will be 'seen double'.

Does this perhaps explain all the 'problems' of our previous discussion?


Under normal circumstances, "how good" an eye is (in terms of visual acuity) has got absolutely nothing to do with dominance. Most people are born with one eye being dominant and, other than in exceptional circumstances, that will remain unchanged for life, even if visual acuity in the dominant eye deteriorates to the extent of being 'much worse' than in the non-dominant eye. I suppose it's possible that, in the very long term, if vision in the dominant eye became very poor, dominance might switch to the other eye, but I somewhat doubt that, and certainly don't recall having heard it being suggested.

In that case I call bullshit again as your goal posts have changed, or should I say double finger

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.

For the tests you describe it makes no difference whatsoever whether you focus on the near or distant object other than seeing the distant or near object double when both eyes are open.

 

[EFLImpudence]

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

No, two ghost like fingers.
Just as two ghost like everything else when focussing on the finger.

I do not understand how it could be otherwise.

 

[SUNRAY]

I'm lucky, both eyes are the same prescription, so I'm generally able to buy the cheap Poundland glasses, and throw them away when damaged- I'm quite tough on glasses, and often break them. I first began wearing them, when I noticed red LED warning lights, seemed to turn a blurred mush. I now tend to wear them all the time, except when outdoors. For driving, they prescribed a very low diopter, so my distance sight, is almost as good without, as with the glasses.

I can usually manage to read even the smallest text, on a screen, without glasses, with just a little narrowing of my eyes. The acuity of my eyes does seem to vary a great deal, some days I really struggle to focus on a laptop screen.

The difference in strength between my eyes isn't significant but I do have a 30° astig which would require a much stronger starting lens to grind the compensation, I only use poundland glasses as like you I damage them, in fack now they are £1.50 or 3 for £5 I tend to buy 6 at a time and keep a stock of differing strengths to use depending on what I'm doing.

 

[SUNRAY]

No, two ghost like fingers.
Just as two ghost like everything else when focussing on the finger.

I do not understand how it could be otherwise.

The laws of physics explain that quite well and John always says they can't be broken!

 

[JohnW2]

In that case I call bullshit again as your goal posts have changed, or should I say double finger

Maybe I didn't explain the test well enough before, but I now have. What I have just described is exactly how it should be done. That was the case when I was first taught the test, nearly 60 years ago (and probably for a long time before that), and has never changed, and I really don't recall any appreciable difficulties on what must have been hundreds of occasions on which I administered the test.
Edit: In fact, having just done some more experiments, it doesn't really matter what one focusses on. That can affect affect how many fingers one sees, and how clearly (or 'ghost-like') one sees things, but it doesn't alter the fact that if one closes one's non-dominant eye, then absolutely nothing changes, but if one closes ones dominant eye, there is substantial change in what one sees.

For the tests you describe it makes no difference whatsoever whether you focus on the near or distant object other than seeing the distant or near object double when both eyes are open.

In a sense I agree with you that it makes little/no difference what one focusses on - at least, not until people start talking about "1 or 2 fingers" etc.

I don't understand why everyone is having so much trouble with this since, as I've just written to EFLI, it is so simple. Having just tried, to confirm, no matter what I focus on, and no matter how many fingers I see, and no matter what is in focus and what is not, if I close my non-dominant eye absolutely nothing changes, but if I close my dominant eye there are clear changes, with some things moving sideways relative to others

 

[JohnW2]

No, two ghost like fingers. ...

Why have you suddenly quoted and responded to a message I posted best part of 100 posts earlier in this discussion?

 

[SUNRAY]

...I don't understand why everyone is having so much trouble with this since, as I've just written to EFLI, it is so simple. Having just tried, to confirm, no matter what I focus on, and no matter how many fingers I see, and no matter what is in focus and what is not, if I close my non-dominant eye absolutely nothing changes, but if I close my dominant eye there are clear changes, with some things moving sideways relative to others

BUT...
With both eyes open, if you chose the other finger/distant combination to cover the result of the test is exactly the same except it jumps the other way