Vestibular Ocular Dysfunction

 

Exploring Autumn

The four hundred kilometer trips to visit my youngest grandchild are an ongoing challenge. It is a challenge that I have not been willing to forego. When I make the trip I am not surprised if it takes me a day or more to recover from the drive. It’s just how things go.

Its not far enough to fly. Taking the train is not an option because of poor connections. So I need to find a way to make it work by car.

I’ve experimented with  different strategies that have changed things up a bit but without reliable improvement. I’ve spread the trip over two days, but that does have it’s drawbacks. I’ve biked the last 40 or 50 kilometers which seems to shorten my recovery time. I’ve experimented with different pit stops. With some pit stops I’ve taken a lengthy walk, while with other pit stops I’ve slept up to 45 minutes. I’ve alternated between being a passenger and the driver. With each of these strategies it’s difficulty to know how much or how little of a difference they make.

It’s difficult to know how effective a strategy is because every situation is dynamic. Each time I make the trip there are related factors that need to be weighed. A significant factor is how well rested I am before starting the trip. The level of neural fatigue before starting the trip varies depending on what I have been dealing with in the previous day or two.

Vestibular Ocular dysfunction

The difficulty is that driving causes neural fatigue as a result of the vestibular ocular challenges. It’s not motion sickness. Rather it’s the movement of objects that momentarily appear in my range of vision and then move quickly into my peripheral vision before disappearing completely. Over time the rapidly changing scenes become neurologically too taxing. The faster I’m driving the greater the effect. I’ve joked about riding blindfolded when I’m a passenger in a car.

As an aside. While I’m biking my speed is so much slower that my brain does not experience the same level of fatigue. At a certain point the brain can no longer keep up with processing all the visual input.

An Exception

I remember making this same trip a few years back. I was alone and so I drove the whole way with only a couple of brief stops. When I had shared that experience with my OT, she reminded me that just because it worked once doesn’t mean I can expect it to work the next time. In hindsight, there was one significant difference when I made that trip… it was a night time drive. With night time driving the visual input is very much reduced with minimal peripheral vision stimulation.

Most recent trip

Before I started my most recent trip I was expecting some real challenges. I had not been sleeping well lately. I had been dealing with some situations that contributed more than usual to neural fatigue. I did not want to use that as an excuse to not visit my grandchild.

Believe it or not, this most recent trip went exceptionally well. I drove all the way. I made three pit stops of 30 to 45 minutes. I arrived at my destination feeling great. No need for a nap or a vigorous physical activity.

What was different

I think the biggest factor is that the whole trip was done in the rain. ((In the past, pre-ABI I always found it more difficult to drive in the rain. Visibility is an issue.) This is partly a guess, but I would call it an educated guess. My extra hint comes from the trip I made driving at night time.

Factor 1: Less image processing. Driving in the rain changes the vestibular ocular affect. Objects in my range of vision were not as distinct and did not come into clear focus. Everything in my range of vision is tinted towards grey. Objects in my peripheral vision were much less noticeable than on a clear and sunny day. It was very much like driving with blinders on.

It reminds me of the horse drawn milk carts that were driven through our village when I was a preschooler. They were outfitted with blinders so they wouldn’t be distracted by extra movement to their left or right.

Factor #2: Slower image change. Driving in the rain meant traffic moved slower than usual. This reduced the vestibular effect. Driving through a major metropolitan area was extra slow. Using cruise control with the pre-collision feature meant I didn’t have to deal with the stress of hitting a car from behind if it should suddenly stop. (I was okay with using the cruise control in the rain because the car also has traction control.)

On this recent trip my pit stops were shorter than usual because I didn’t feel like I needed as much time. When the first part of the trip went better than usual, I decided to make this trip an experiment. I wanted to see the effect, given the rainy condition how I would fare if I drove the whole distance myself. Had I found myself getting drowsy or having difficulty focusing I would have switched from driving to being a passenger.

Factor #3: Smooth roads. Some roads have concrete surfaces with expansion joints at regular intervals. Once the road has settled a bit, the rhythmic ‘thump’ as the tires hit the expansion joints becomes too much to handle. In the same way, a rough road with many potholes is also problematic.

Conclusion

I know that this trip went very well. What I outlined and the reasons for it going well is still somewhat guess work. If I’m correct about the effect the rain has on  my vestibular ocular challenge, that doesn’t get me out of the woods so to speak. I can’t expect to do this trip in the rain every time. In fact, the next time I do this trip it will be winter and the reduced visibility will likely be caused by snow. That will increase the challenge by creating new stresses.

So maybe I should buy some blinders. (Anyone have a horse that doesn’t need them any more?) Maybe it’s worthwhile to do part of the trip blindfolded. In truth, I don’t find either idea appealing.

A consideration

Instead of waiting for rainy weather, I do wonder whether wearing tinted glasses might make a difference. People with Scotopic sensitivity syndrome* (more commonly known as Irlen Syndrome) benefit from wearing tinted glasses. Testing is done to determine which colour is most helpful.

If tinted glasses has such a profound effect on people with Erlin Syndrome it might help with vestibular ocular challenges. Both conditions are related to processing what the eye perceives.

A  more practical consideration

While I’m not sure about using tinted glasses, I have seriously considered wearing sunglasses. My one question is whether wearing sunglasses when it is overcast is compromising my safety. Do sunglasses reduce visibility too much , and therefore compromise safety, when it’s not sunny out?

* Note:

Scotopic sensitivity syndrome

According to Irlen, these difficulties lead to reading problems, eye-strain, headaches, migraines, and other physical difficulties that can be alleviated by the use of person specific tinted lenses, known as Irlen Spectral Filters, worn as glasses or contact lenses.     https://en.wikipedia.org › wiki › Irlen_filters