Friday, September 28, 2012

Ken: Making a Life with Double Vision

Youtube keeps suggesting videos to me and I looove this one. This double vision case was not caused by long standing strabismus but is the consequence of a brain aneurysm. Because of the totally different cause and the severeness of his brain injury this is not treatable with vision therapy as it is in cases of strabismus. Notwithstanding the double vision is just the same... Maybe I should even be happy I can work on my problem through vision therapy. Take a look at this amazing testimony :)

Tuesday, September 25, 2012

One view

Before, meaning my whole life, I had to chose between my left and right eye (alternate). The last five years, in a double vision situation, I would see both images but only one eye is really aimed at what I am trying to see while the other one is just bugging me with a floating image. The alternation was not that 'clean' anymore, right and left were getting jumbled up into something horrifying. Now that I am slowly adopting single vision I noticed that when I am aiming both eyes at the same point I can't really distinguish anymore between the left and the right eye. It's just one view. The frustrating part still is that it is so easy to fall back to double vision. The slightest bit of physical effort or loss of concentration can make the eye alignment go away. My gaze isn't neurologically fixed yet... It's going to be another dark winter but at least I have a good forecast!

Friday, September 21, 2012

The basal ganglia and what they do for you

There are many educational apps out there, but the best I've found for neuroscience is '3D Brain'. It's available for Android and iPhone. I love it.

Brain structures that seemed of special interest to me are the basal ganglia. The basal ganglia comprise a group of structures that regulate initiation of movements, balance, eye movements and posture. They are strongly connected to other motor areas in the brain and link the thalamus with the motor cortex. The basal ganglia are also involved in cognitive and emotional behavior and play an important role in reward and reinforcement, addictive behaviors and habit formation.

The brain doesn't work according to linear rules. For instance, fifty percent of the brain is involved in visual processing although this doesn't mean that fifty percent of the brain is dedicated to this task exclusively. When it comes to the brain multitasking is the name of the game and everything is connected to everything. Hence it's impossible to make a simple road map of how the brain works without including several dimensions.

Source: Cousera - Introduction to Clinical Neurology
Lecturer: Jill L. Ostrem

The basal ganglia are located relatively close to the center of the brain, meaning very close to the brain stem. Even though the brain is a holistic entity, together with the thalamus these particular structures operate as a foundation or portal to many other more complex functions. So when we are talking about binocular vision problems, an imbalance exists at the core of the brain (in the great majority of cases the eyes or eye muscles are perfectly fine) and not only affects vision but also other functions administered by the basal ganglia and brain regions depending on it. Thus it should not be surprising that binocular vision dysfunctions can cause poor concentration, headaches, balance problems, learning disability, psychiatric disorders (alcoholism, depression, schizofrenia,...), motor problems and is highly correlated with juvenile delinquency. When such problems occur a comprehensive binocular vision examination should be the first step. Vision Therapy taps into the life long ability of the brain to adapt to stimulus according to the principle of brain plasticity and provides the tools for bringing some balance into a disoriented visual brain.

Additionally, in a book I have recently been reading called 'The brain that changes itself' by Norman Doidge the basal ganglia or basal nuclei are said to be of utmost importance in the process of neuroplasticity. By learning new skills or an entirely new language for instance processes that are constantly active in a young child during the critical period will be reactivated. During this critical period a child doesn't differentiate between important and not important stimuli and is constantly in learning mode. A child takes in everything without distinction, just as you do with a foreign language you don't understand. Over time as we grow up we do start to differentiate and get into a more permanent mind set, however engaging in new activities can help us change the brain life long. Novelty stimulates the basal ganglia to accommodate those changes more easily by producing certain chemicals and to some extent keep the critical period going. This does not only have implications for visually impaired people but also for autism, dementia  memory loss, ... Since the basal ganglia play an important role in keeping the critical period 'open', it allows for managing brain plasticity for the better. It can allow for visual or auditory processing problems to be resolved by gradually 'reprogramming' the brain or rejuvenate elderly people by reviving their brain with new mental activities. The role of the basal ganglia in maintaining mental and physical fitness through learning and experiencing new things is truly impressive. A pioneer in this field and its practical application is Dr. Michael Merzenich with individual training programs such as Fast ForWord for learning disabled and autistic children and Posit Science for the elderly.

Last but not least, I want to share this video emphasizing the role of the Basal Ganglia in motor coordination. It is tempting to try and simplify the brain but that would be an injustice. What seems to be true however is that the basal ganglia are directly and indirectly responsible for the overall health of the brain and body and stimulating it throughout life has many benefits on top of 'just learning a new thing'. It has the potential to, to a certain extent, prevent or even reverse neurodegeneration.

Related articles:

Session 41

Life after the zero degree angle. Since now I have a zero degree angle (aligned eyes) most of the time I can see a clear distinction between the time I am pointing my eyes correctly and the time I'm not. This is the 'advantage' of having double vision as opposed to suppressing the second image. Obviously I try to point my eyes properly as much as possible. The best way to achieve this is to sleep well, rest and not overdo anything. As is true for all strabismics things get harder by the end of the day. It's very important I try to see well without pushing it. Aim for quality, not for quantity. At first it's better to drive well than fast. After you can drive well and fast (but not too fast:)). Once your skills reach a certain level, you can apply them on the road. So whenever I'm awake, I have to take care of my eyes. This requires a lot of discipline and self control because virtually every activity involves eye sight. I can live with a limitation of freedom that serves a higher purpose (being healthy 3D vision) that is worth doing it for.

I don't have much to say about todays session... Trying to improve and extend existing and upcoming skills will take more time and work so we are just doing that. Home work: PC exercises, a wooden wheatstone stereoscope and a prism flipper to use while reading.

Thursday, September 6, 2012

Check-up 5 (After one year and eight months of VT)

Today was check up time! They measured the progress in numbers. Over this one year and 8 months I've come 14 degrees of difference initially to 8 and then 4, then 3 and now finally ZERO! This means most of the times my eyes are alligned. I noticed this before by intermittant single vision showing its head. Now it's official :) Thing to do next is keep it up and automize it. Make this visual system more flexible untill ultimately 3D vision kicks in. 3D vision is the goal, it's the key to locking down this progress. Without it, if I were to stop, I will just regress to where I started. So it's not over, but definitely good news!

Maybe later I'll post a schematic overview of the evolution of my progress over this extensive period of time for completeness' sake.