A horse and hemianopia

369A1C63-F808-4A4B-97B2-B0C5F7005F6BYou might be looking at this photo of a horse and thinking, What the heck does a horse have to do with CVI? With my child’s hemianopia? Recently a horse drawn hayride, pulled by these horses, provided a perfect example of what happens with hemianopia.

Visual field preference – or visual field deficits – is one of the ten characteristics of cortical visual impairment, CVI (Roman). Damage to visual fields is diagnosed as hemianopia: “Hemianopia, sometimes called hemianopsia, is partial blindness or a loss of sight in half of your visual field. It’s caused by brain damage, rather than a problem with your eyes.” That fits right in with the definition of CVI as a brain based visual impairment. It is a problem with the brain, it is not a problem with the eye.

In the midst of the other CVI characteristics like color, light, movement, and especially complexity (in all its manifestions: complexity of array, complexity of object, complexity of the human face, sensory complexity, clutter) – visual field deficits or hemianopia seems to take a back seat to the other, flashier characteristics.

My son’s hemianopia, or visual field deficit, is a frequent problem at school and beyond. More than once, visual field deficits have resulted in “behavior,” which basically means a fight or flight response to something that you did not, could not, see coming.

Hemianopia is a problem everywhere, really. Too often I hear myself reminding instructors: “He can’t see to his left, so he won’t see you if you walk on the left side of the horse.” Back to the horse.

At a weekend festival, there were horse drawn hay rides. To me, all horses appear enormously strong, especially when my young child is riding atop one. But these draft horses were truly physically impressive, the veins in their muscles bulging. These were work animals. You would not want an unintended encounter with one of them.

Between hay rides, while waiting to load up, you could walk up to the horses for a closer look. Hippotherapy was one of my son’s therapies for a long time. So horse etiquette is pretty familiar. In fact, given the long relationship between humans and horses, you would think horse etiquette would be in the public consciousness. You could possibly forgive somebody for not knowing about CVI, but don’t most people know you do not to approach a horse from the back or side?

First to board, we claimed a spot right at the front of the carriage, behind the handler. As we waited for others to climb aboard, people approached these impressive animals. The horses were clad in their tack, which included blinkers or blinders. Blinkers are worn to block peripheral vision so that the horse is not distracted or panicked by something it sees to the side or behind. For the horse, the blinker created a hemianopia, or visual field deficit. We already know not to approach a horse from the side or behind. But people did it anyway.

At that point, the horses’ handler, a grizzled, older man, had had enough and barked at the crowd:

“The horses can’t see you on the side! They can’t see what’s touching them!!”

It seemed so obvious. You would be surprised how often it is necessary to remind people of your child’s hemianopia.

At school, in the general education classroom with other children who also have a hard time sitting still, not because of CVI but because they are kids, my son often gets unexpectedly bumped, shoved, poked. He can’t see you on his left side! He can’t see what’s touching him! He does not see it coming and interprets contact as intentional.

The horse handler yelled just the way I sometimes want to yell about my son’s hemianopia, or complexity or movement, light, latency, distance. Often it seems like visual field is one of the easier CVI characteristics to understand. But you would be surprised how often people need to be reminded: He can’t see you on his left side! He can’t see what’s touching him!

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