It is because these exercises are forcing us to do consciously
movements that are supposed to be happening all the time when we are using our eyes, hopefully is all waken part of the day.
Which are they, you might ask! Well, the answer is convergence and divergence.
The definition is this:
- What is converging/diverging?The axes of eyes. Both axes of left and right eye need to cross in the focus point in order to see the point clear
- What are axes?Axes are straight lines that are passing thru horizontal surface thru the pupils of the eye and thru the centre of the pupil.
To move axes we use extra ocular muscles. - Seeing closeTo see object close axes need to converge or cross.
- Seeing distanceTo see objects in the distance the axes diverge or open to go more parallel.
- In blurred vision...axes are not crossing in the focus point.
In addition, - Nearsighted or shortsighted person (seeing close and having blurred distance objects)
instead of diverging their axes are converging (this is what I noticed my eyes are doing) - Farsighted or longsighted person (seeing distance objects but not seeing close)
they are unable to converge or cross eyes, they are unable to cross eyes enugh close to see close object clearly, that's why they tend to move image further away from their face and sometimes it's being said - the arms are just not long enough (this especially in presbiobia or aging reading problems) - Crossed eye or strabismusmy thinking is that as their axes actually cross in opposite direction, behind the head instead in front of the face, so therefore the functions of converging and diverging of axes is completely distorted.
Just to add, when viewing these 3D images or stereograms along with moving axes there is additional operation that is happening in order to create the hidden image (or third image in the middle with stereograms) and that is mental sliding of attention along the axes. That is exactly that function that is moving force to make us do these movements of convergence and divergence.
And then it functions as every muscles work out, what we exercise becomes more and more natural instinctive function. The one thing is with all these functional vision problems that there is impulse from the brain is there but muscles are too weak to make the movement.
Or, the other thing is that the brain commands are confused - as I mentioned instead of diverging they converge.
My recommendation for exercise from all this discussion:
- One to three daily sessions of 50 converge-diverge exercises or 10 mins
- Doing this with the image in all angles:
- directly in front of the eye
- up
- down
- left
- right
- diagonally (up-left, up-right, down-left, down-right)
- Every session is good to be followed by 5-10 mins palming
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