In Part 7 I alluded to why a set of procedures like Infinity Walk was powerful in therapy. It seems increasingly we work with patients who have some sort of visual-vestibular integration issues. If they have undertaken any sort of vestibular rehabilitation therapy (VRT) they may have come to us having been prescribed a form of Cawthorne-Cooksey exercises to undertake at home. These are also relatively simple looking procedures that tap into the complexities of visual function, and are sometimes described as gaze stabilization exercises, as depicted here.
We find that many of these patients have had difficult doing these procedures because they lack the underlying visual abilities reflected in procedures such as thumb tracking and rotations, or four corner wall saccades. Of ours the inverse can be true, where patients experience instabilities because their unaddressed vestibular issues are limiting their ability to handle the flow of the visual world. Much of this can be addressed with slow changes initially in terms of degree and rate of movements, and the changes in angle of gaze or rotation.
A colleague, Dr. Gary Williams, pointed out that the current discussion of eco-optics reminded him of a book I recommended quite some time ago entitled Active Vision: The Psychology of Looking and Seeing, co-authored by two gents from the UK.
One can define active vision as an analysis of visual space that involves eye movements, head movements, and movements of the body. It often involves optic flow fields and motion parallax. I haven’t looked at the book for quite awhile and sure enough, when I pulled it off the shelf, it was littered with colorful stickers I used at the time to highlight important points. One of them was Findlay & Gilchrist’s constructive criticism of J.J. Gibson’s ecological optics theories for placing too much emphasis on the environment and not merging it adequately with what was known about the eyes and vision. Fair enough, and we’re doing our part to bridge this gap.
For our talk this Friday in the UK, Sue Barry picked out this quote from A.M. Skeffington, the principal architect of behavioral optometry: “He who is insecure in his space world is insecure in his ego”. One of the premises that we’ll be elaborating is the interaction between what the patient is internalizing and externalizing in her visual processes. We’ll delve into this next ….