INTERVIEW: Nick Swaans, construction worker turned stereo vision builder

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Nick Swaans is 25 years old, lives in Beerse (Belgium) and describes himself as a true born builder. With his 1,88 meters of length, Nick has an imposing stature. Some have described him as being a “rough diamond”. Professionally, Nick is active as a construction worker at the Total oil refinery in the port of Antwerp. His specializes in groundwork, by both hand and machine. Usually he likes what he does and works long hours. At one time he was even escorted outside from his station by plant security because he had been working too many hours in one stretch.


Total oil refinery in Antwerp

Recent picture of Nick Swaans

Recent picture of Nick Swaans

In his free time, he tinkers with his old jeep.  He refurbished the thing from scratch and participates in 4×4 off-roading competitions with it. Nick was weaned on off-roading. His father let him drive on private roads starting from the age of ten. Consequently, he’s not a guy afraid to get his hands dirty. Nick jokes, “I just can’t sit still. I’m into mud professionally as well as for leisure!” Another favourite pass time of his is fishing which he has been doing ever since he was five.


Aside from work, driving and fishing, he also likes to go for a walk in the woods after work. “The industrial environment at the refinery is very thick. The kind of soil I’m working with is not just regular mud, it’s all mixed up with oil and chemicals. This mixture and its fumes give off a very pervasive smell. It is a real pleasure to get away from all that and enjoy nature.”

Being a Belgian, he also enjoys drinking his Belgian beer. “Every so often we go to a bar after work. Not all bars are equally happy to host us because we might still have mud all over our clothes and even faces. Fortunately, there are still some old school pubs that don’t mind a couple of dirty workers. Hanging out at the pub and having a beer is like social media but better. Some people don’t realize that anymore.”



Another aspect of Nick’s life are his vision problems. Nick has amblyopia and intermittent strabismus. Nick Swaans first contacted me through my Dutch language strabismus website ‘‘ on March 4th, 2014. This is the translation of his message:

“Hello Michael,

I’m Nick. I’m 23 years old and have had a lazy eye for 20 years.
I work in construction and it can be pretty challenging without depth perception.
I have consulted various eye doctors and had the necessary tests done. Alas, nothing else can be done about my condition anymore…
Particularly annoying to me is the crossing of my eyes when not wearing glasses or contacts. 

If you know of anything that might lead to a solution, I’d like to hear about it.

Kind regards,

I responded to his question and gradually learned more about his particular situation and how strabismus and amblyopia are intertwined with his life.

“I think, I have had a lazy eye (amblyopia) since I was five, or at least that’s when it got detected. I had a picture from when I was five with a patch covering my inferior, lazy eye. And another one where you can see my lazy eye turning away. I don’t have those pictures anymore. I threw them away during a fit of anger and frustration about that damn eye.”

3 or 4 years old

“This is a picture from when I was three or four years old and everything was still fine visually. The amblyopia and strabismus must have come on when I was five.” ,- Nick Swaans


Nick’s is a clear case of developmental accommodative strabismus/amblyopia. His strabismus and amblyopia came on because of undetected and optically uncorrected farsightedness, or hyperopia. This partly impeded completion of proper neurological visio-motor development. “I’ve permanently worn glasses between the ages of 6 and 18. Between the ages of 5 and 12, my prescription lenses were adjusted almost annually moving towards increasingly thick glasses. These glasses also contained cylinders for astigmatism. From twelve years onward the thickness of the lenses started to decrease and I wore the same glasses for multiple years in a row.  Then, between 18 and 23, I’ve barely worn any specticles.”

An eye doctor once told Nick his vision condition was hereditary. I explained to him that seeing was a learned process and amblyopia had much more to do with stimulation, practice and appropriate optical correction than ‘genetic predisposition’. In a sense, although the optical correction of his farsightedness was a step in the right direction, it was not enough to put binocular development back on the right track without eye teaming training. The way it was administered comes down to ‘too little, too late’.

“I’ve been wrestling with this eye problem my entire life and now I notice that the situation is deteriorating. I’m considering having eye muscle surgery which is the only option eye doctors offered me. Every night I notice my eye lid shaking but I guess that’s just because of over-exhaustion. My eyes start to cross when I’m tired, especially while watching TV. I only experience double vision when watching TV or when I’ve been drinking.” 

These are interesting observations. Drawing on what Nick tells me and my own personal experience, I have some ideas about the why of all this. In cases of intermittent strabismus, movement and balance exercise are often an impetus to align the eyes. I can think of two reasons for this.

First, when in motion, the vestibulo-ocular reflex (VOR) is activated to keep the eyes aligned and maintain a consistent, single view. This also helps with navigating in space. In order to avoid motion sickness, whether while walking or driving, the body puts in extra effort to avoid a conflict between the eyes (the visual) and the inner-ear balance organ (the vestibular). To do so the organism, if capable, will align both eyes aided by the VOR. This might also be one of the reasons why Nick likes to be in motion and ‘can’t sit still’.

I once heard a beautiful example of this. A little child, who was born cross-eyed, was increasingly becoming less so because of VT procedures or stimulation adapted to the infant. The strabismus came to be more and more intermittent. A particular instance when the eye turn seemed to straighten out was while being in a moving car. In order to try and avoid motion sickness (or car sickness), the child’s body tried to sync the images from both eyes with the input from her vestibular inner-ear organ. The conflict between the visual and the vestibular was temporarily being resolved. The child continues to have more and more ‘aligned eye time’ through proper stimulus and guidance.

A second reason for why it is often easier to align the eyes when moving in case of intermittent strabismus, is the difficulty of moving the eyes separately from the head or body. I actually experienced this myself. To some extent my head moved along with my eyes in an attempt to maintain a clear and single view in search of visual comfort. Not only did my eyes not move independently from my head, but neither did they move independently from the entire body! After a while it was so difficult to maintain a single, comfortable view, the whole body would tense up. The point being that, sometimes, body parts do not have enough of a neurologically specialized movement ‘repertoire’ to move independently. In this case, to move the body means moving the eyes and to move the eyes means moving the body. To move and align the eyes then, might require to move the entire body until more specialized and independent eye movements are embedded.

Even when the eyes are still misaligned, movement generates additional sensory input such as for instance tactile input. Such additional input distracts attention from the visual sense and makes it easier to suppress one of the two misaligned images. This is why Nick only notices double vision when watching television. 


Nick’s primary complaint, apart from the aesthetic aspects of the occasional crossing eye, was his lack of good depth perception. “Lack of stereo vision bothers me most of all. I miss it every day.”


“I can excavate cellars, install sewerage and so on, only leveling out the base/foundation is more difficult for me than most of my peers. I’m no longer allowed to work with the crane or handle heavy machinery. Given my lack of depth perception, my foreman is of the opinion that it would be too dangerous. He doesn’t trust me to do the work. “

Photos taken by Nick during dig training

Photos taken by Nick during a job training

"Without stereo vision, excavating a level plane as a result is a real challenge! Although some other guys needed more guidance from the instructor than me. Makes you wonder..."

“Without stereo vision, excavating a level plane as a result is a real challenge! Although some other guys needed more guidance from the instructor than me. Makes you wonder…”

“Feeling comfortable when working with a crane and mastery of heavy machinery is very important to me. Being told I can’t do so is a major personal and professional blow. I also put my pursuit of a CE driver’s license (a license for trucks and heavy machinery) on hold. It’s so stupid to have this dream shattered because of a lazy eye! There has to be a solution.

From our first virtual encounter onwards, I had continued to explain how VT is the safest and most promising way to go about improving visio-motor skills and possibly acquiring stereo vision. Several months later Nick had still not been assessed by a behavioural optometrist. He had toyed with the Tetris game provided by this blog but it started to dawn on him that he might need more specific guidance.

“Visual Training is an option but I’m facing a shortage of time. I’m working long hours so time is very much an issue. To ever acquire stereo vision must be amazing. This lack of good depth perception bothers me a lot. I miss it every day.”
On October 15th, 2014, Nick had his first optometric assessment performed by Kristel Soffers (VTOD). Nick received some good news. “According to the tests I do have some depth perception, a little at least. I was very glad to hear I did have some stereo vision.” This is indeed a very nice point of attack when starting a course of Vision Therapy.


When Nick entered Kristel Soffers’ office for the first time, he was wearing glasses containing following correction:
OD (right eye): sph +2.75 cyl -0.75 ax 180
OS (left eye): sph +3.75 cyl -0.50 ax 180

He had been wearing those glasses for about a year but was also wearing contact lenses containing this correction:
OD: sph +2.75
OS: sph +3.75
(No astigmatism correction)

Kristel’s visual examination yielded somewhat different results in terms of refraction:
OD: sph +3.50 cyl -0.75 ax 180
OS: sph +3.75 cyl -1.00 ax 165


One of Kristel Soffers’ primary strategies when starting Nick’s VT was to work towards a higher acceptance of plus lenses. In other words, spherical lenses to correct farsightedness. As Nick would adapt to the increased strength of the + spectacles, this would have two benefits. It would relieve some of the strain and relax his lens focussing ability (accommodation) and, at the same time, make the eyes drift out naturally (vergence) to bring the esophoria, and at times even micro-esotropia, under control. This would ultimately also enhance his underdeveloped stereo vision ability.

Basic visual skills

Basic visual skills

Initially, Nick would go on weekly VT sessions. For starters they worked a lot on simultaneous perception (with both eyes) and anti-suppression. They also tried to improve the acuity and neurological receptivity of the left eye. Improving vision and activation of the left eye in particular has not been easy. In fact, acuity levels of the left eye have not increased dramatically but binocularity and eye teaming has significantly improved. Acuity in the left eye would fluctuate strongly from week to week. The measured cylinder needed for the left eye (astigmatism) would also fluctuate wildly, both in terms of power and direction of axis.

Acuity training
in the left eye would be very straight forward. He would try to read an eye chart from increasingly farther distances. Nick would tell me, “Initially I couldn’t read the letters with my lazy eye at a distance of one meter. Now I can read it from two meters away.”

and simultaneous perception was done by using polarized vectograms, anaglyph targets and a biopter.



Biopter Cards

Biopter Cards

There was also plain old saccade training and training to widen eye movement and fusion ranges. This involved base-in prism flippers in free space using a brock string. Another exercise would be something akin to eccentric circles on what Kristel calls ‘vergence paper’. Prism flippers would also be used in combination with the biopter. The biopter cards provide anti-suppression controls which are important.

Eccentric circles on 'vergence paper'

Eccentric circles on ‘vergence paper’

Accommodation flexibility and plus lens acceptance would involve the aforementioned exercises in combination with spherical flippers.



Towards the end, tying all these new skills together Nick would practice on what he calls the depth perception device. It’s a rather primitive looking device. He has to grasp the target  in free space without any filters or anti-suppression controls with millimeter-like accuracy. The adequate completion of this exercise wholly relies on his new stereo vision guiding eye hand-coordination.

Depth perception device

Depth perception device


On October 30th, 2014, Nick remarked that “after only two days of training I’m already noticing a difference.” By April, 2015, after only half a year of training, things really started looking up. “I’m really starting to have a lot more depth perception, also in daily life! I practice my VT procedures every evening but most have gotten too easy. At work I continue my practice with a spade or other tools and machinery I need to use. I’m getting pretty damn good!” He concludes, “I’ve come a long way in only six or seven months! I would never have expected that beforehand.”


During this period of VT, the + power of Nick’s day lenses was systematically increased. This went fairly swell. Eventually lens acceptence was raised to +4.00 for the right eye and +4.25 for the left eye. For this high amount of spherical power, there is no cylindrical correction available within the contacts, says Kristel Soffers.Nick really loathes wearing glasses. When he takes out his contacts and puts on his glasses, his eyes cross a little. He even avoids mirrors and busy places because of his spectacles. “I really prefer contacts. My eye sight is much clearer when wearing contact lenses. When wearing contacts I also feel as if women look at me differently. All of this taken together means that wearing contacts really improves my self-esteem.”

This profound hatred of glasses made it all the more worrisome when his contacts started to irritate the surface of his eyes. He was developing  corneal neovascularization because of his contact lenses. “I tried working without my contacts for one day but it was too dangerous, certainly in my branch of work. Finally, I conceded and turned back to my glasses. Sadly those gave me a headache at that point.” To avoid further endangering his ocular health, he was forced back into his glasses. Consequently, Kristel renewed his specticle prescription in accordance with the higher plus lens acceptance they had been working on to avoid more headaches.

OD: sph +3.75 cyl -0.75 ax 10
OS: sph + 4.25 cyl -0.75 ax 165

This prescription adjustment happened on April 9th, 2015, during Nick’s 18th appointment. Up until now they had been working with weekly appointments. As this period of intensive training had yielded plenty of fruits such as the onset of greatly enhanced stereo vision, appointments would be planned every two weeks only from now on.

The inability to wear contacts and the impracticality as well as the unwillingness to wear glasses posed a new visual problem to solve. Once again, he began searching for a lasting solution.
His advising behavioural optometrist, Kristel Soffers, suggested looking into implantable contact lenses (ICLs). He consulted Dr Ben D’heer who investigated whether he was an eligible candidate for ICLs. He was.
Nick underwent a corneal topography (pictures with the red placido rings). This procedure meticulously measures and maps the cornea and any irregularities it might have. Based on these and other measurements, it was determined what kind of lens and how exactly it would be inserted to be tailorfitted to Nick’s eye.
corneal topography

Corneal topography device

corneal topography chart
corneal topography 2
Before placing the lenses, an iridotomy laser procedure would have to take place to lower fluid pressure within the eye. This way the lenses can be fitted without causing damage to the inner-eye because of dangerously heightened fluid pressure. This is why iridotomy, making an small opening in the cornea to drain fluid, is also used to prevent or treat glaucoma. “When I bend over to pick up something I really feel there’s less of a pressure build-up in my eyes. It’s pretty amazing.”
iridotomy laser-iridotomy
At the time of this writing, the iridotomy procedure has been completed but the lens placement has yet to happen on December 21st, 2015. “Apparently that’s also the doctor’s birthday. Hope he won’t be to elated and inebriated because of the occasion”, Nick grins.
By April 26th, 2015, Nick’s stereo vision was a fairly constant and noticeable presence in his life. “My stereo vision is very obvious. Stereo vision and being able to perfectly assess distance at the glance of an eye is truly a blessing.” When I asked him to elaborate, he spontaneously came up with a bunch of examples of how it improves and enriches his daily activities. 

“For instance, nowadays at work I can level out piles of sand with solely a rake, trowel and a shovel. I can just SEE the plane is level! I don’t need any measuring equipment to make sure. Just the other day, I was very proficient when working with a machine called a “mini-digger”. My foreman was just dumbfounded! He doesn’t know what is happening given how problematic it had been for me in the past.  I’m still not allowed to work with the crane but that will probably change in the future.”

“Or when setting up a fence and installing barbed wire. In the past, a very brave person with balls of steel would have to hold the pole while I was hammering the fence poles in the ground. I would regularly hit fingers. The same would happen when putting nails into wood. Now I don’t hit fingers anymore. I hit the pole accurately and they are instantly spirit level/plumb by relying solely on my vision and depth perception.”

“Even my fishing practice has improved. Before, when casting my fishing line and net it would often end up in tree branches rather than on the desired spot. Now, I can perfectly estimate the distance and cast my line without problems. I also use this little gps guided boat for carrying my rod. If I wanted my little boat at the other side of the pond close to a tree, say a meter in front of it, I would have to guess. I would keep steering the radio guided boat until it touched the tree and I heard a scraping sound. Then I knew I had gone too far.  Now I don’t have to bump into things and listen to the scraping sound to know exactly where the boat is positioned.

vis 1vis 2

Nick never had trouble driving but now he finds it even more enjoyable. “I’ve been driving since I was twelve and my father took me to 4×4 events. Driving is second nature to me. Since I have depth perception the experience is much richer though. When being on an off-road track with some hills for instance, I can see the little hills within the hill. I can judge the nuances and repercussions of taking a slightly different route much more clearly than before and get stuck less often. It’s a huge advantage. Parking is also easier, even though I parked fine before.”

offroad4 offroad5 offroad1
As a teenager Nick used to hate school and was regularly kept in detention for causing trouble. I wondered whether he used to have reading problems similar to mine. He didn’t. “I never really had reading problems, I even read rather fast.”

I also asked whether, now that he understood that he had been missing a crucial vision component up until now, he felt this had impeded him at school. “No, not really. My last course of in school training was carpentry but after school I decided that stuff wasn’t really for me so I went into ground works.”

Despite all this good news, the development of his new stereo vision, giving him an entirely new dimension, is not entirely without set backs. “Some days are better than other days and on the occasional very bad day my stereo vision can temporarily be greatly reduced. That’s annoying.” There is still work ahead but all in all this is a happy ending. “If it wasn’t for you and your website I would probably have had the muscle altering strabismus surgery as the eye doctors recommended. That would have been a huge mistake. Thanks for that, buddy.”


As his vision is coming together and this is stabilizing work performance and career prospects, he is planning to implement some extra changes to his life. He is looking to buy an old house and, as he’s pretty handy, wants to renovate it himself. He’s also pretty fed up with the single life and hopes to find a woman to share his muddy adventures with. When ruminating about this quest he states that “a woman who likes all this muddy stuff is very hard to find.” Being of the optimistic disposition, I think this too will work out soon enough. Every Jack must have his Jill!
maslow hierarchy of needs

Click to enlarge

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This article has 3 comments

  1. Sarah Reply

    Congrats on the improvements in your vision, Nick! It’s so amazing to find out all the ways life improves when your visual system begins working more like it’s supposed to.
    I really appreciated the explanation of why double vision may occur more while watching tv also. Even though my vision overall has improved greatly, I still notice quite a bit of double vision while watching tv, and your explanation about it having to do with a lack of movement fascinates me. I do notice less double vision when I’m using the tv to do a workout dvd, so this actually makes a lot of sense, but never occurred to me before. Interesting!

  2. Andrew Waranowski Reply

    Wow! Great article. Implantable contact lenses! You saved this guy some pain, Michael. Well done! I guess you could say that this ‘strabismus awareness’ stuff is doing quite a bit of measurable good.

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