'Bouncing vision' is an attempt to explain the term oscillopsia. Because of an irregularity within the vestibular system, the eyes of people with 'bouncing vision' do not keep track of targets well, lose them, and have to hunt around to lock onto them again.
When I walk, my head bounces on my shoulders - so does yours! This is called the 'doll's head reflex'. You know those little Elvis dolls on the dashboard. Bounce. Bounce. Bounce. Your eyes follow the bounce of your head so close to instantaneously it is imperceptible. My eyes don't. There is a delay. The target is lost, I can't find it, I look for it, all the time walking forward. The ground (or the gutter, or the approaching bus) rears up in front of me and I, understandably, lurch.
In hunting around trying to explain all this in an understandable way, I found some videos that might help. Serendipitously, the videos were made by the chaps at RPA, and use the technique that they use on me. Disease of the vestibular system is 'vestibulopathy'. This can be unilateral or bilateral - because there is a system behind each ear! I have bilateral vestibulopathy.
This first video shows a chap with unilateral vestibulopathy. I will use the term right meaning to the right of the screen - NOT his right. And similarly for left. Okay? When his head is jerked to the right, you can see his eye have to adjust. When his head is jerked to the left, his eye is there nearly instantaneously.
This second video shows a chap with bilateral vestibulopathy. His problem was caused by exposure to a drug called 'gentamicin' which mine wasn't. But you can see the hassle here in both eyes. They have to adjust, they have to find the target.
Remember, there are four issues feeding into my hassles. Issue 4, I will discount first. Well, not so much discount, as simply not go into, because I don't know where it fits in except that there is a correlation between people with Issues 1 -3 and Issue 4, which is a raised paraprotein in the blood. This was first uncovered by a routine blood test in 1996, and revealed to the Balance Team at RPA when they got my history from the Balance Centre at St Vincents, where I had been attending to have my toes and fingers 'electrocuted' in 2002 - 2005 whereupon I got jack of it all and simply went AWOL. The biggest problem I had at that time was the peripheral neuropathy. In summary:
Issue 1 is the peripheral neuropathy (PN)
Issue 2 is the Bilateral Vestibulopathy (BV)
Issue 3 is the Cerebral Ataxia (CA), and
Issue 4 is the raised paraprotein, also known as MGUS (Monoclonal Gammopathy of Unknown Significance).
And the pattern here?
The PN affects my walking because I lose track of where my legs are because they are sending my brain less information. I still have good 'proprioception'. I know where my legs should be. Like a phantom pain in an arm that has been amputated.
The BV affects my walking because of the ocillopsia and the bouncing vision.
The CA affects my walking because that is what ataxia is - disturbed gait. The cells are being lost from the vermis between the two halves (how many other halves are there?) of my cerebellum. My step is not smooth, and my feet when they come down can cross over the hypothetical centre line of the forward progress.
Yet to come, so they tell me, is the affect on my speech known as dysarthria and the affect on my memory known as dementia.