www.strabismusworld.com

This blog has moved to www.strabismusworld.com. Everything that can be found here can also be found at the new location, as well as new articles.

The new site:
- provides more overview and a system of categories.
- has a text-to-speech feature when highlighting text.
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Vision Stress Testing: 5K Run

April 14th, 2015

After being out for a couple of years and focusing my energy on my vision, I decided to slowly give running another try. Running is not my main focus but I try to use it as complementary training to my vision rehab. That is, when I feel I can handle it and won't go in overload.

It's unfortunate that these mistreated vision problems have dragged my physical and neurological condition down to such an extent because I used to be a natural at running. My performance should be peaking rather than dipping right now. I've never done many races in my life but so far I have done 5K, 10miles (16K) and a half marathon (21K). I decided to do another 5K race in 12 days. I'm looking forward to it but I'm keeping expectations low. I think I can do 23 minutes but we'll just see what happens. If I clock at 25 minutes, that will be alright too!

Here are some of my previous running results. If I can have the same outcome as in 2012, it is a de facto improvement because my vision (ocular motor control) is much better now than it was back then.

April 28th, 2015

I immediately added the results of this year to the image. The race went pretty okay. I started out easy and then, after the 3KM point, deployed whatever energy I could muster. During the last kilometer my vision was getting very shaky. So much so that I barely recognized my awesome friends who were cheering by the side of the road. Fortunately you don't need that much vision to run your longs out. When I arrived I was very dizzy but I fairly quickly recovered my normal (current) level of ocular control. I did not revert to double vision. Running the 5K wasn't the actual challenge. The challenge was to see what would happen afterwards. Would I be able to function normally and get home or not? To my delight I did alright. My nervous system and ocular motor control recovered enough not to be a zombie for the rest of the day. We went to grab some food and we had a nice day without me crashing.

Nonetheless, it remains interesting to see these time differences. I attribute it to the following cause (but I could be wrong). When I was younger, I would have a very low resting heart rate. When checking my heart rate, doctors would always ask me, 'Do you do any extreme sports?' or 'Are you doing sports on a professional level?'. I didn't. I didn't even run that often. Just when I felt like it, which was usually on Sunday. I was simply physically strong from having to endure academics with limited visual skills. To me, reading is much harder and physically taxing than running.

Sadly, these days my resting heart rate is not that slow anymore. I have the occasional panic attack and have to endure the stresses of an unrecognized handicap without income replacement or compensation for medical malpractice. The only thing I can do is wait and do my vision rehab which has been a very long and arduous process without breaks. Fortunately, relatively speaking, I can now see light at the end of the tunnel. I was lucky to find enough support and have played my cards flawlessly to get to this point. Now over the next year or so I have to finish it. I think that only after having acquired the security of reliable vision and body performance and hopefully, God forbid, a steady income stream, I will get some peace and might be granted a more slowed heart rate once again. Being more relaxed from time to time helps your body recover and allows you to build reserves. In that case of a slow heart rate, you can elevate that heart rate to a much greater extent when it is actually needed for physical performance. This instead of heart throbbing from being cornered and betrayed or the occasional, and ultimately useless, panic attack when dealing with a visually (and otherwise) unstable world.

Nothing is more crucial to the survival and independence of organisms—be they elephants or protozoa—than the maintenance of a constant internal environment. Claude Bernard, the great French physiologist, said everything on this matter when, in the 1850s, he wrote, “La fixité du milieu intérieur est la condition de la vie libre.” ,- Oliver Sacks

Aperture Rule: A Vision Therapy empathy top tip

As you might know, at this point my eyes are looking pretty much normal most of the time but the inability to converge consistently remains crippling. It drains and strains a lot. It's like a massive extra backpack I'm wearing, or an invisible barrier between me and the world, preventing me from getting things done more easily.

Currently, much of the time, I'm living with a male cousin named Thierry (22) and female cousin named Cynthia (26). They are very nice about my peculiar situation and try to understand. I, in turn, am very patient in trying to explain my neurological vision problem even though, after all this time, I'm often fed up trying. By now, however, I am getting quite proficient at linking theory and experience into a coherent narrative. More importantly, they are really interested and concerned on a personal level so it's worth the effort to make them understand more fully. I'm really lucky in this respect because that quality is not something that can be taken for granted. They even defend me and try to re-explain the issue when other people ask them, "What is your cousin doing with his time all day?". They try to grasp and explain the reason why I am seemingly unproductive. Because of the nature of this problem, I know it's nearly impossible for them to understand completely but they are very considerate and do their best. That's a prerequisite for true communication.

To my delight, Thierry, who is also an engineering student, got so interested that he wanted to perform some of my exercises himself. Earlier we did some trial runs on the Cheiroscope and he was very good at it. His drawings were very stable and deliberate and his corners nice and sharp. That was to be expected. The fact that my drawings aren't stable and deliberate is basically the only reason I didn't end up to be an engineer in the first place.

 Now, what was even more interesting is our experience with the aperture rule. The aperture rule artificially dissociates accommodation and vergence. In other words, it makes it harder to use both of these basic visual functions appropriately to see a single AND clear image. The goal of this exercise is to further automate and incorporate these skills and enable the patient to use them without effort. This is an often re-occuring theme in Vision Therapy. The Rule has 12 levels for convergence and 12 levels for convergence depending on which Aperture plate you use. I, myself, am not super-solid on any level but my best performance, including head turns while viewing, is at level 4 using the double aperture (divergence setting). Generally I am more at ease with the divergence setting but I can only go up until level 6 before the target picture doubles up.

In the convergence setting (single aperture), I have often trouble keeping a clear and single image regardless of the level. Much depends on my fatigue level but generally there is improvement. When well rested, I can go up to level 6 or 7 when keeping my head still and focusing intensely. With head movements things tend to jump around. After all, this exercise is particularly hard because of the artificial dissociation of accommodation and vergence. It is my dream to be able to do the aperture rule fluently and without too much effort up to level 8 or 9. Well, the higher the better but let's start with that. Good stuff ahead! Can't wait!

Let's get to my point. I had both Thierry and Cynthia do the Aperture Rule. I got them to do convergence which they could do well, as I expected. They could go all the way up to level 12, albeit with some effort. At the higher levels they started to need some time to fine tune their vision to adjust to the heavy load of seeing both singly and clearly. They started to have the experience of having to work for your vision! They uttered things such as, "I can see it but I can't see it well", or "It takes a lot of effort!". Thierry even said, "You've explained your vision issues so many times but this is the first time I REALLY understand what you were talking about. It must be so exhausting having to work for your vision in this manner ALL the time!" Afterwards he said he was very tired.

For my part, I told them they were fortunate because in modern life convergence is most important when it comes to completing daily living tasks successfully. My inability to converge is the main reason why I'm out of service. Then I had them try divergence. They were completely floored. They even had trouble figuring out how to see level 1 correctly. Maybe it was not an inability to diverge but rather an inability to grasp what was expected of them. It's not always easy to figure out the Aperture Rule the first time you encounter it. Nonetheless, Thierry was intrigued. He remarked, "Apparently I have a visual limitation. I don't like it. I want to improve, especially as I want to try and become a pilot later on." 

There you have it, people. A Vision Therapy empathy top tip: the Aperture Rule. If you can't shake your vision problem easily or quickly, make 'em join you!

Cheiroscope: video, drawing samples and implications

After a nice theoretical post, let's get down to the nitty gritty. How can we get a tangible look into how someone perceives his personal space? How can we determine inconsistent perception of space interfering with the construction of solid brain maps?

As vision writes spatial equations for the muscles to solve, cheiroscopic drawing is an interesting way to gauge the state of ocular motor ability and spatial vision. During cheiroscopic drawing, one's visual system is completely stripped of contextual aids. Broader context often helps strabismics to get around and complete certain tasks by circumventing proper ocular motor movement or spatial vision and by relying on sub-optimal, monocular vision adaptations and other senses. When using a cheiroscope none of that is possible. Your drawing hand and fingers HAS to take its cues from the eyes. The movements of the hand are based on the movements of the eye. If the eyes are positioned well, move together in a smooth and harmonious manner and can maintain a steady posture, you will succeed. If not, you will come up with an inconsistent and skewed drawing. It's that simple. A direct connection. No more adaptations, no more tricks, nowhere to hide from your visual shortcomings. It's a head-on confrontation with your visual limitations but also an opportunity to improve and to chart and compare that improvement over time.

I made a little, informative video about a cheiroscope that can be used at home. I apologize in advance for the constant movement of the camera. My video recording skills also need more work!

Here are some more of my practice run results produced by using that device (March, 2015). They are each of them unique and contain small mistakes. The variations in the drawings are variations in my vision and ocular stability. My vision is still volatile and unstable. Yet, it's a far cry from where I've come from years ago. This maze is very detailed and requires a fairly sophisticated level of ocular control on which to base your solution. Merely being able to try this exercise is already a triumph for me.

Let me show you where I've come from, going all the way back to February, 2011. For that purpose, I will be showing drawings made by me with another type of cheiroscope. This is a standup variation of the cheiroscope. It is called the Wolff cheiroscope named after Bruce Wolff, OD, who designed it.

Recently, at the VT office, we were comparing some cheiroscopic drawings I had made over the years. These pictures compare the results of the same cheiroscopic drawing exercise. The upper drawing was done on October 16th, 2012. The lower drawing was done on March 16th, 2015.

The relative position of the drawings is different because of different eye positioning. Also the quality of the drawing itself is markedly different because of improved ocular stability. In 2012 the left hand drawing was so inconsistent that the sun wasn't even staying her box. Hell, there was not even a clear box! And, as someone acutely pointed out, now the suns do have a smiley face!

What's even more startling is the fact that, on October 16th, 2012, I had already been in Vision Therapy for one year and eight months! Here are two cheiroscopic "Van Orden Star" drawings comparing February, 2011 to October 16th, 2012. The drawn lines should converge onto the highlighted fold. In the first drawing, in 2011, this certainly wasn't the case. I had a considerable vertical misalignment too.

Van Orden Star

Notice that, in the picture with the sun drawings, the upper drawing was drawn on the same day as the lower Van Orden Star drawing. This nicely demonstrates that improvement is relative. On October 16th, 2012, I was delighted about my improvements regarding the "Van Orden Star" drawing. However, the more visually demanding and detailed sun drawing exercise left much to desire. Now, another two years later, the sun drawing too have improved significantly and I will continue to go down this road of more ocular stamina and accuracy. The only thing one can do is to consider his current vision status and keep on stacking incremental improvements to eventually get to a better place in the future.

My primary vision therapy goal is not stereo vision. Stereo vision seems to be a combination of various basic vision skills. Overcoming the crippling legacy of strabismus surgery, which has thoroughly destroyed already ailing basic vision skills, is my primary vision therapy goal. To be specific, I need smooth tracking, reliable saccades and a stable vestibulo-ocular reflex. When I accomplish that, I'm golden. From what I hear, stereo vision will be a nice bonus on top of having these basic visual skills. These basic visual skills by themselves are pretty awesome too though! Without eye muscle surgery, I would already be seeing in stereo! However, as the cards have been dealt this way, these extra hurdles have to be taken. There is no other way.

Me and my Vision Trainer summarized the current situation as follows. "No one would have thought you would have come this far when you walked through the door, more than four years ago, but now you possess the basic visual skills. You can see through both eyes, you start having fairly good eye motility, you have some fusion in polarized targets and you can even figure out depth in tranaglyphs with a reference object like your finger or a stick! You have all the ingredients and now have to go a little furter and combine them into a good menu." 

The only missing ingredient is more time and work. I can do that. The cloak of subdued dysfunction is slowly lifting itself. I have mentally prepared myself it might take until January 2017 for me to reach workable levels of vision. After six years, I think, this Vision Therapy thing will start to lose some of its charm. Hahaha. Cheers, everyone!

The visual system's important role in figuring out where you are

Developmental strabismics often learn how to suppress sight coming through one eye. Many times they even learn how to alternate between both eyes. This is a useful short term neural adaptation but has many disadvantages in the long haul if not corrected. Having been, and to some extent still being, an alternator, I know how it works in practice and how it feels. If feels like you can shift between two ways of seeing. You are not only switching between your physical eyes but also between two viewing positions in your mind. You litterally have two "mind's eyes". When paying attention to this weird ability and supposing your head/body is a vehicle you are maneuvering, it feels like you can change the driver's seat's position. One moment you are in a normal car. The next moment you are in a Brittish car. You can shift what is called your visual midline (visual midline shift). When I was younger even colors used to look slightly different depending on which eye I was using! I remember when I was fourteen asking my mom: "When I switch from one eye to the other I sometimes get color changes. Do you also get that?". Reasonably enough she didn't really understand what I was talking about and had a disturbed look on her face!

In developmental strabismics the act of alternation is often a subconscious one. Because we developed this way we can usually apply it to our benefit as much as possible. It's not optimal but if you master and control it, it can be manageable. For me problems started occurring when, firstly, this learned visual neuro-adaptation started to unravel by itself due to external pressures (because it is not an optimal nor stable neural equilibrium).  Secondly, these problems were aggravated when the correspondence between how my eyes moved physically and how my neurology worked was radically disrupted through eye muscle surgery. That is why the first couple of days after surgery I even had to relearn seemingly simple acts such as keeping balance and walking. On the surface I learned quickly but a lot of extra unnecessary baggage had been added to tasks of daily living. I did my best to pick up the pieces and held my own for a couple of years but ultimately it was not possible to just forget about the problem and live a normal life. Untangling this neural and physical dissonance is a work in progress.

...

That is why following passages taken from the book Vision Rehabilitation strongly resonated with me. These can be found in Chapter 4 on Spatial Vision, written by Robert Sanet and Leonard Press.

"While walking, patients with ABI may demonstrate a shift in visual midline and altered gravitational sense termed visual midline shift syndrome (VMSS). These patients demonstrate balance impairment and associated motor dysfunction, including leaning, falling, or veering to one side during mobility. VMSS can have an immediate and dramatic effect on the motor dysfunction. 

The sense of awareness of one’s position in space is predicated on what has been referred to as “the invariant.” Without having a stable frame of reference of self, it is impossible to organize space efficiently and accurately. As an example, consider what it would be like to find the location of a specific place on a map using only the coordinates “two miles west and one mile to the north.” One cannot derive the answer without knowing the initial piece of information: “From where?”

 The invariant provides a stable frame of reference upon which we build spatial constructs. The mental representation of space, and perception of straight-ahead body orientation, are related to a number of internal reference frames, including visual, vestibular, proprioceptive, and tactile information that allow us to build accurate spatial maps. That is to say, the brain orchestrates movement using a series of internal models, maps, or schemes of external reality. Even before initiating the movement, the brain has already taken the visual information, anticipated the consequences of the movement, and formulated a series of motor actions to accomplish the goal. The antigravity system, therefore, relies on the integration of many neurological processes, principally as follows: 

- Visual system input that aids in the determination of vertical and horizontal frames of reference, and the perception of self-motion that comes from optic flow patterns across the retina. 

- Vestibular system input through the otolith and semicircular canal systems of the inner ear give information about head position relative to gravity, and changes in acceleration and deceleration. 

- Proprioception system input from the stretch receptors in the muscles that give information on body position.

Visual input to the vestibular and proprioceptive systems that direct movement, such as when adjusting balance or moving the body and hand to grasp an object or to catch a ball, is due in large part to subcortical “unconscious” visual pathways. The automatic, unconscious visual prediction and computation that supports motor planning and execution of accurate motor movement is often disrupted when patients experience ABI. This results in visual-spatial confusion and inaccurate visual guidance of motor movement."

This short clip by the BBC nicely demonstrates how disrupting changes to visual input can be for balance and motor ability.

I particularly like the concept of having a stable frame of reference of self in relation to the environment constructed upon various sensory streams of information referred to above as "THE INVARIANT." Vision plays a crucial role. Simply put, the visual system has four essential questions to answer:
1. Where am I?
2. Where is it? (an object or objects of interest)
3. What is it?
4. What do I need to do or say about it?

If that primary sense of awareness of where one is in space (the invariant) has become variable because of conflicting visual information due to for instance eye teaming difficulties, the answer to the first question has been compromised. If the invariable becomes variable, spatial uncertainty is compounded. This will have far-reaching effects on the visual system's ability to answer question 2 to 4. This interference and uncertainty will negatively impact the ability to oversee situations, interact with objects or find relevant information. Secondly, it will also compromise movements, memory, verbal ability and might cause serious fatigue and mental confusion. In short, without controlled and stable visual input to the brain, the ability to interact and build proper spatial brain maps suffers greatly.

...

To get back to my own story... Nowadays my, what is supposed to be, invariant is all too often variable and this has a profound effect on my ability to function. I am physically strong but this leak in the system can throw me off balance and drain my energy without mercy. I like to move but I do it in settings where I can easily retreat when needed. Over time my variable invariant is getting more fixed and coherent. When I have good moments and have relatively high amounts of ocular control, I can see abilities and talents I knew I have had all along flaring up. If I can get my invariable to be invariable more often and hopefully indefinitely, the sky is the limit.

One example of this is a basketball video I recorded a few weeks ago on "a good eye day".

This is pretty good for having no stereovision.  However, I cannot play like this consistently. Same goes for reading performance or any other kind of performance. It depends on whether I have good or bad ocular control that day or that moment. As optometrist Myron Weinstein once said: "Vision writes spatial equations for muscles to solve." Can my brain rely on the visual and proprioceptive input provided by my eyes?  Isn't it too exhausting to get my eyes in line? Those factors will determine how variable my "invariable" is at that moment and how well I will perform.

"We are never tired as long as we can see far enough"  ,- Emerson

Fortunately I know I can improve indefinitely, even with damaged eye muscles, and I will. As there is no other option but to do this rehabilitation thoroughly, I should not settle for damage control but I should try to unify these two alternating monocular ways of seeing into one coherent binocular system. This in turn will contribute to my body's sense of position, motor abilities and my ability to construct brain maps of any kind.

If you are interested in learning even more about strabismus, suppression and brain maps, I had a first attempt at making a watchable video tutorial about this topic. Enjoy!

Jaw clenching, Vision Therapy and earthquake resistant structures

Personally I learn a lot from reading/listening up on vision rehab and anatomy but I learn just as much from having conversations with other strabismics. I think it's a practice that could be useful to anyone with any problem. Don't compare yourself to people with a very differing, in this case neurological, background. Learn from people who are similar to you and dealing with similar day-to-day problems. What follows is a blog post constructed on this type of conversation.

PASQUALE: Hi Michael, in many blog entries you mention jaw clenching. I too have said that I engage numerous facial muscles while I try converging and diverging at different targets.  It feels like the brain is recruiting other muscles because it still hasn't figured out how to properly use the eye's extra-ocular muscles.

MICHAEL: I always think of it like learning how to do something with your left arm (unless you are left-handed). First you use your entire arm, often in a contorted way. Then you move on to more specialized movements of the joints and ultimately you can do things smoothly having very fine control over your arm, hand and fingers. Theoretically the potential for improvement is limitless.

Let's transpose this to the visual realm. At first, when trying to accomplish a visual task, you are doing it very clumsily and inefficiently. Your brain is trying to accomplish a task which requires fine ocular motor skill but it's not succeeding because of a lack of (lasting) control. Because many of us are hardheaded we redouble our effort and adjacent regions and resources like facial muscles are drawn into the process to little or no avail. Not good. Instead of redoubling our effort employing a very limited set of visual skills we should go back to the drawing board and improve and multiply our skills. Technique is more important than 'brute' force.

The visual system involves six of the the twelve cranial nerves. That's a lot of guns to fire and potentially misfire. When I experience jaw clenching after too much reading or just a visually or otherwise stressful situation, that implies I've gone beyond my current visual skill level and I need to back down.

Trigeminal nerve - 5th cranial nerve

PASQUALE: Have you figured out exercises that eliminate engaging other muscles except for those needed to coordinate the various components of the eyes.

MICHAEL: Well, any activity that encourages 'the eyes', meaning the appropriate muscles and neural processes associated, to do the work without recruiting other muscles. That implies not going too far beyond your current skill level and paying a lot of attention without getting frustrated. For me it means slowing down and lowering expectations while gathering finer motor control. As long as my jaw doesn't clench, I'm in the safe zone. Once I start hurting, I'm overdoing it. It's not always easy to be patient and sometimes there are just visually stressful tasks I have to deal with. Then I'm tired, dizzy and in pain.


When thinking about this problem I'm reminded of something I learned about earthquake resistent structures. There's no such thing as a completely earthquake resistent building but you can improve a buildings capacity to withstand external shifts to a large extent. There are various approaches you can adhere to when going about the seismic retrofitting of a structure.
- You can increase the global capacity of a structure. (strengthening)
- You can isolate the foundation so the structure can shake on it. (partial flexibility)
- You can impose intelligent structural changes. Structural vibration control technologies minimize forces and deformations. (flexibility)
The last option implies that various individual parts of the building can move or flex allowing for shock absorption.

Vision Therapy is akin to a seismic retrofit for the visual system. You make structural changes in how it works and learn how to control and flex individual parts. You learn to lean into a quake rather than stiffening up.  That way you can withstand more external demands, with reduced energy drainage and avoid collapse of the structure/system.


For me, eye teaming remains a big challenge but I'm getting there. A related challenge is to gain more independent control over vergence and accommodation, i.e. taking on any binocular stance while manipulating my eye lens as I please. Either component should have limited effects on the other one's performance and there should be a certain ease in doing this. Just like using indivudual fingers while playing the piano.  An increased 'isolation' of these visual components gives more freedom of movement. To continue the piano anology, you'll be able to play 'visual Mozart' instead of just hitting the keys indiscriminately with all fingers at once.

As far as particular exercises are concerned, there are plenty of options to choose from if you understand the underlying principle. Magic eye stereograms, prism/spherical flippers, Eccentric Circles, Aperture rule, even just playing freely with your vision, ... Many VT practices are grafted on this idea one way or another. They are looking to improve smooth eye teaming, lens focusing and then increasing skill level by adding more activities (balance, body coordination, cognitive skill, ...).

In that respect, I particularly liked a quote from the interview I did with Mark last month. It illustrates this point very nicely.

MARK: I still have strabismus but I have a greater degree of control. The reduced suppression helps. I can line everything up that I need for stereopsis (fixation on an object, in focus, no suppression, awareness of peripheral vision etc.). It can be an enormous effort but it's like any other form of learning. Repetition is the key and progress, however slow, will be made!

The only catch 22 when talking about all this 'control' is that you won't necessarily attain it by going about this like a control freak. Be relaxed, patient but determined.

One month later... 

PASQUALE: It has taken me over eight months to finally feel that my brain can move my eyes with better coordination without trying to recruit a battery of other facial, non ocular muscles. I have gone through an entire slew of other muscles including those around the temple region, jaw, even moving my ears. The worse was when I actually felt my upper jaw putting tremendous stress on my entire skull as if trying to separate one from the other. I have to say that I see more positive progress now that my brain isn't trying to move my eyes through the recruitment of all those other muscles.

Mark B, strabismic pilot with eyes on the skies

Around a year ago I met Mark B. through our DIY Vision Therapy Facebook group. Every so often he'd post a picture of a little airplane or an air field on his Facebook profile. I thought he must really like planes but since he was strabismic he probably doesn't fly them himself. Turns out I was wrong!

MICHAEL: Hi Mark, where do you live and how old are you?

MARK: I live in the Brittish midlands, in Redditch more specifically. That's just south of Birmingham. I'm 39 years old and will turn 40 this year.

MICHAEL: When did you develop strabismus? 

MARK: As far as I know it's congenital, although the term "strabismus" is relatively new to me. Growing up it was simply a "lazy eye" which was "treated" with eye patches. The patching was a regiment of forced reading with one eye. I don't think the patching did anything to align my eyes and improve the strabismus as such. At the time I didn't really know why I was doing it either. However, clearly the patching helped me keep vision in both eyes (avoiding amblyopia which is another relatively new term for me) so I'm grateful for that!

MICHAEL: So just to be sure... You never had eye muscle surgery, right?

MARK: No, the patching happened around the age of 5 or 6. Then, I can't remember exactly, maybe around 6 or 7 I had a few hospital visits and had lots of tests. They wanted to do eye muscle surgery but I was horrified and refused!  Over time I learned to control my eyes so they looked straight(ish). On the other hand, I also learned to suppress vision in one eye and developed a distinct head-tilt. I'm glad I never went in for the surgery. My parents were cool with backing out of it and never made a fuss about it.

MICHAEL: Clever kid, good for you! Did you have a hard time academically? What did you study?

MARK: I do remember when I was very young, reading was very difficult for me. I had above average intelligence and a very inquisitive nature but I struggled to read words as they jumbled all together. I would lose my place when moving to the next line. Over time, my reading got better as I learned (as I now realise) to suppress the image from one eye. At school I studied Science and went on to study Physics at university.

MICHAEL: Cool, what kind of work do you do currently? 

MARK: I'm currently working for a water company. It's a great job. It takes me to a lot of different places and I meet a lot of interesting people.  I work as a planning and scheduling manager - I've got groups of people dotted around the place who organise crews to go and respond to customer issues and make sure we maintain the pipes and overflows so we don't cause pollution. There's a lot to keep me busy!

MICHAEL: Sounds like an interesting and useful job! Water is important. How then did you get involved in aviation?

MARK: I started flying a few years ago - just a lesson a month which was very slow going. I've always liked planes and the idea of flying. It was my wife who suggested I should start flying lessons. I never really believed I could afford it or have the ability. I trained for a few years and got my private pilot's licence last year.

MICHAEL: That's awesome! What a supportive wife you have! Did you have to pass some sort of vision exam to obtain your licence?

MARK: To get a private pilot's licence you need a class 2 medical which involves a reasonably thorough medical examination by an aviation doctor including a "routine eye exam" (basically medical history, no "abnormal" eye conditions, a reasonable level of visual acuity and colour vision although the latter only restricts night-flying).

Last autumn I got the crazy idea of pursuing a career path in aviation (commercial work or instructing) but for that I would need a class 1 medical (thorough examination including very detailed ophthalmology exam, cardiogram, audiogram, blood tests etc.).

I spent a day at Gatwick airport doing this but failed due to strabismus. The guidelines for a pass on the vision exam are:: -

(1) At 6 metres:
2.0 prism dioptres in hyperphoria,
10.0 prism dioptres in esophoria,
8.0 prism dioptres in exophoria;
and
(2) At 33 centimetres:
1.0 prism dioptre in hyperphoria,
8.0 prism dioptres in esophoria,
12.0 prism dioptres in exophoria
 should be assessed as unfit.

MICHAEL: I guess they placed prisms in front of your eyes to elicit certain reactions and those were your limits or something...

MARK: I failed due to 8 dioptres hypertropia . My eye positioning was not fixed and would change all the time, even during the measurements. My eyes were just out of my control! They also said it would be very unlikely that I would ever be issued with a class 1 certificate. Nonetheless, at this point I was allowed to renew my class 2 medical (fit to fly - hooray!). That was when I finished my private pilot licence course in Feb 2014.

MICHAEL: It's too bad you were assessed as unfit for a class 1 certificate! Nonetheless, you seem to be endowed with an analytical mind and can do attitude. A problem needs a solution, right? How did you discover VT?

MARK: I think I learned about VT just by searching the web for 'strabismus cures'. I did a bit of research. I went looking for real evidence on websites that they genuinely viewed Vision Therapy as a serious and effective branch of optometry.  I have also seen some websites advertising VT as some kind of miracle cure or pseudoscience which put me off... Anyway, I found several good websites and eventually I also found your blog!

MICHAEL: I always love to hear that people find my blog! Did you ever read Fixing My Gaze? 

MARK: I did, it is a fantastic book! I really like the way it relates to Sue as the person and how she feels and relates to the world rather than Sue solely as the objective scientist. Definitely gave me hope despite years of dogmatic medical opinion that there is nothing that can be done with strabismus apart from cosmetic changes through surgery!

MICHAEL: When you first found out about VT you experimented a bit on your own, right? 

MARK: I did try some VT stuff before I started formal VT appointments but this caused me a lot of frustration. I think I was over stretching myself and trying to work on alignment and fixation without considering the basics like muscle control, attention and posture.

MICHAEL: Here are some of your group updates from around that time: 

January 21st, 2014

"Had an interesting couple of days. I'm experimenting with different things myself at the moment before handing over money to somebody who says I will never see in stereo.

The anaglyph Tetris is going okay but it's hard work. I'm still not fusing both images into one so it's like trying to guess how many columns to move the piece to land it. Interesting though, I thought my left eye wandered upward but it moves slightly to the right as well! I know it's helping me overcome suppression but it is hard!

I'm having much more fun trying to view 3D anaglyph (blue/red) photos, I'm finding that if I relax my eyes and un-tilt my head (I have a head tilt), I get fleeting moments of 3D vision. I tried to explain to my wife that it's like suddenly looking through a piece of glass in front of your face and everything looks beyond or in front of that piece of glass. Everything looks a lot clearer and sharper as well. Those fleeting moments are quickly lost but will hopefully build up.

I'm getting brief moments of stereo vision in every day life as well. They're few and far between but getting more frequent. This is going to take some serious time but I believe I will get there!"

March 26th, 2014

"Last week I felt I was getting somewhere. I worked on some crossed eyes stereograms for a couple of weeks and started to see in 3D in the real world but it was short-lived! I just went back to flat images and vague 'shadows' of the eye that tends to suppress. I'm going to sort out formal Vision Therapy in the next few weeks... I can't do this on my own!"

MICHAEL: How did you find your behavioral optometrist? You seem to be having very good experiences with the practice you are going to.

MARK: I looked on Google. They are surprisingly hard to find! I think I ended up on the BABO (British Association of Behavioural Optometrists) website www.babo.co.uk. Fortunately I found a behavioral optometrist around 40 miles away which isn't too far. I went with Keith Holland and associates in Cheltenham as it looked really professional and they seemed to genuinely care about what they did. The vision therapist has been working in this field for many years and really takes time to make sure we spend our time productively and focus on the right areas (no pun intended). I really cannot praise them enough and really look forward to our sessions! It is difficult to gauge my own progress as I am, by my very being, subjective but I have really improved my visual range (i.e. movement range of the eyes), ability to focus on specific points and stereopsis when viewing stereograms. I see the Vision Therapist every month and I think I'm due for a review with the optometrist every six months. I have a long way to go but I've definitely got some momentum going here!

MICHAEL: Yeah, you also went in with some fleeting moments of stereopsis which is a nice starting point! I would sign up for that any day! Here are some more group updates you posted after you officially started VT. I always liked your updates as they are so positive and excited.

August 27th, 2014

"Well, I finally had my first appointment with a behavioural optometrist today. I was warned that I might get permanent diplopia (double vision) if VT breaks my suppression but I can't fuse images. That's just something that could happen. The alternative is living with the strabismus which I don't want to do. I should get some news next week about starting proper vision training!"

September 15th, 2014

"I started vision therapy today!!! It went really well. The therapist said that a lot of people in my position (i.e. late thirties) find out about VT and start a program having done a lot of research and having a good idea of what it is about. As it was the first session, we covered lots of different things.

One thing that surprised me was that there was emphasis on balance and perception of surroundings. It had something to do with re-wiring the brain and creating new neural pathways in order to accept 3D vision. For instance, for one exercise I wore a pair of prism glasses which gave me instant double vision (no suppression). I had to look at my hands in front of me (there were four of them) and we went through each one (numbered 1,2,3 and 4!) to make me believe each hand was real. I'm not entirely sure what the purpose of this was but I will ask next time - possibly starting anti-suppression?

Anyway, I've got an eye-patch and my own brock string with a timetable of daily exercises for next time. I'm working on balance (walking in a straight line with legs crossing in front of each other), eye stretching (patching one eye and fixating to the far ranges of the unpatched eye) to strengthen the muscles and to "convince" the brain that it would be good to start looking in places where I currently cannot, and a brock string. I'm trying to get the "V" shape. I'm sort of struggling so far but I will persevere! There was one brief super exciting moment where we had a go at a polarised stereo pair plate and I could "see" one circle "in front" of the other. I've had brief flashes of 3D before but this was quite controlled. Apparently neurons going into overload and building new pathways when that happens! Looking forward to more of that! Next session in four weeks!!!"

September 19th, 2014

"Almost a week later and I'm starting to really break things down. The brock string is great. It shows you how things really are. It gives instant feedback on whether both eyes are "switched on" and if you're really fusing/fixating on an object (rather than your brain telling you not to worry about it!). Doing big eye muscle stretching exercises every day. I think they're helping. I can "fix" a bead on the string after doing stretches. It's just going to take some serious repetition and practice. Onwards and upwards!"

October 14th, 2014

"I had my second VT session on Monday and we covered loads! I tried brock string with red/green glasses which really helped. It seems to help break the suppression as the two images are clearly different colours. I've now added those to my VT pack. We did some more balance work with prisms to alter my view point. We're working on centering my brain and body. My VT is big on looking at vision as a holistic sum of many parts, not just the eyes!

Did some more work on the polarised tranaglyph. I'm sort of seeing depth but really struggling without another reference point to compare it to. I've been given some homework to work on hand/eye coordination and estimating depth by threading a straw with a cocktail stick and to keep with the brock string.

A final thing we did was called the "Van Orden Star" which is a bit like a stereogram lensed viewer where you join opposite sides by drawing with a pencil to where you think they meet. I think it gives an objective visual representation of how you see the world (how your eyes are positioned, that is). One side seemed higher than the other which would make sense. We're going to do it again in a few months to see how I've improved (!).

In every day life, I'm suppressing less by fixating on objects with my eyes more rather than turning my head. This is bringing on some diplopia but it is completely within my control and is useful feedback on where my eyes are pointing and how far I am off. I'm sure my brain would prefer I didn't do this but it's tough.  It's going to have to adapt I'm afraid! I am getting regular flashes of "depth" also - very briefly but more often. I just need to keep pushing myself. Onwards and upwards. This VT stuff really does work."

ANDREW: Apparently you have some 3D vision and it's gradually getting stronger and stronger. It doesn't seem that you just suddenly *got* it. Some people mention 'layers of depth' in regard to object array auto stereograms without really seeing depth in every day life. It seems like it's a sort of low-level stereopsis. With higher-level stereopsis, I'd imagine that you would see depth exactly as you would Y and X dimensions. 

MARK: Yes, the depth I see is something I've discussed a lot with my Vision Therapist. I refer to it as relative depth as I can differentiate between different depth planes in a very real way. They seem nearer or further away. Nonetheless I really struggle with tying that up with their absolute position in space. I think judging absolute positions of objects and the environment by stereoscopic depth perception is a learned skill which most people learn throughout infancy. For us strabismics, however, it's another step in the Vision Therapy chain of neural learning.

ANDREW: Do you have still have strabismus, i.e. a perceptible misalignment?

MARK: I still have strabismus but I have a greater degree of control. The reduced suppression helps. I can line everything up that I need for stereopsis (fixation on an object, in focus, no suppression, awareness of peripheral vision etc.). It can be an enormous effort but it's like any other form of learning. Repetition is the key and progress, however slow, will be made!
  
MICHAEL: Things seem to be moving in the right direction for you! That was October last year. How have things progressed since then?

MARK: Ever since I started formal Vision Therapy I've been making leaps and bounds of progress. It's been hard for me to judge as things don't happen quickly but I have regained a lot of muscle control and I have a better degree of stereopsis. For example, when I was first assessed, I was shown a stereoacuity test "the fly" which was just a polarized stereogram of a fly. I was asked what I could see and, with my alternating suppressing ways I answered that I could see two slightly different images - it depended on which eye I looked with. I had completely forgotten about this when I was shown it again a few weeks ago when I saw a fly with different levels of depth, it was very clear but I didn't know what the big deal was! These things creep up on you, I think I had been doing a lot of stereogram tests and failed to appreciate the progress I was making! For me, the results are not dramatic and immediate but do build up over time. I'm amazed at how little understood and acknowledged VT is in the medical community given that they estimate that 10% of the adult population has stereo-blindness due to vision alignment problems. Every time I have had an eye test they tell me that my vision is perfect, 20/20 and that I have nothing to worry about and nothing can be done except for surgery!

MICHAEL: How does Vision Therapy fit into your aviation activities and plans?

MARK: I am currently doing some more flying courses (flying on instruments, night flying) to keep the flying going while I go through Vision Therapy. Flying will always be fun even if I don't ever work in aviation. Nevertheless, I do plan to go back to Gatwick sometime and get my class 1 certificate and who knows where I'll go from there. I do intend to keep working my full time job for the time being but the eventual aim is to get a full commercial licence and train to be an instructor. I think I'll retire as a flight instructor in the Scottish highlands, taking people on pleasure flights. In comparison to my current job, flying is so much simpler but much more exciting and with a better view!

MICHAEL: That sounds like a great plan. It's good to have plans and goals to aspire to. It will certainly keep you motivated. Thanks for taking the time and good luck with everything you do, Mark! Onwards and upwards!