Friday, June 8, 2018

Sensory Processing Difficulties: Sight (Part 3)

This is part 3 of a series on Sensory Processing Difficulties.  Part 1 was on touch, and part 2 was on the proprioception and vestibular senses.

Brain-Eyeball Communication

So, usually when people think of their sense of sight, and things going wrong with it, they think about the physical eyeballs, glasses, eye charts, etc.  Perhaps red-green colorblindness comes to mind, or cataracts.  While those are certainly important, when I say "visual sensory processing difficulties," these are not what I mean.  There's nothing physically wrong with my eyeballs (well, besides some nearsightedness): the rods, cones, and optic nerve are all just fine.
 
Instead, sensory processing difficulties are:
  • disorganization in the muscles the brain uses to control how the eyes focus
  • oddities in how the brain itself processes the data sent to it.  
One or both of these can affect a person, and because vision is such a basic sense, people tend to take it for granted and assume that others see the exact same way they do.  Particularly when the eye doctor tests come back with no significant problems.  But, like me, just because the eyeball and optic nerve is in good health, you aren't guaranteed to not have problems with your vision. 

Brain-Muscle Miscommunication

A normal person can follow the path of a bouncing ball down a driveway, for example.  A person with muscle-coordination visual processing difficulties might not be able to do that.  Their eye muscles may not track the movement properly, and as such, the ball escapes their field of vision and is gone.  They might also have difficulty keeping their eyes on an object as they move, find it hard or impossible to read lines of print in order, or find it difficult to change between looking at a blackboard and looking at a book on their desk.

The end result of these problems can include tons of headaches, regular squinting, frequently losing your place while reading a book (and continuing to resort to using your finger as a guide), trouble copying information from a blackboard, difficulty reading signs or your dashboard while driving, avoidance of stairs, and even avoidance of groups of people due to the dizzying difficulties of keeping track of them all. 

Again, this is not something special glasses or surgery can fix. It's a oddity in the brain itself.  The brain itself can be trained by a specialist, and accommodations made so the person can slowly work toward more normal visual processing. 

Visual Hypersensitivity

This comes in all kinds of exciting flavors. 
  • Light sensitivity: oversensitivity to LEDs, sunlight, fluorescent lights, camera flashes, other bright lights, and/or glare from light sources.
  • Contrast sensitivity: separating black text on a white or off-white page is easy to most.  Not to these folks: the letters can seem to blur into the white page rather than being sharp and defined, which makes it very hard to read.  
  • "Tunnel reading" or restricted span of recognition: difficulty reading groups of words or letters together.  This can make it hard to move from line to line in a book or article, read for the content as a whole,  and even copy words from a page. 
  • Impaired print resolution:  in which the letters on a page or a computer screen are unstable, shimmer, or even move.  Again, makes for bad times when needing to read books, reports, or blog posts written by snarky autistic adults on the Internet.
  • Environmental distortions: like impaired print resolution, except with whole objects moving, shimmering, or changing.  Stairs, the faces of family, and even the floor itself can become  anxiety-provoking.  
Light sensitivity is by far the most common vision complaint I hear from fellow autistic people, and I myself suffer from it.  You can find yourself overwhelmed quickly in otherwise normal situations, even to the point of feeling like the light is stabbing your eyeballs or brain.  This is particularly true with LEDs, which have gotten more and more popular in headlights and even regular lightbulbs.  There's something about the quality of the light that makes it harsher and brighter than incandescent bulbs.  The constant glare can make people tired very quickly, or even become dizzy and develop headaches.

Things like "walking into sunlight," "looking at clouds in the sky," and "looking at snow" can all hurt my eyes.  Even on an overcast day in winter, the whiteness of the snow can reflect enough light to cause stabbing pain.  Headlights at night are awful, particularly if someone's forgotten they turned on their brights.  I usually have to resist the urge to shut my eyes entirely while making rude gestures at the thoughtless jerk.  And that's assuming those headlights aren't the newer LED ones, especially the blue-tinted ones.  If LED headlights are involved, chances are I'm going to suffer if I'm anywhere near them.  

Also, camera flashes.  Can I just say that they're basically the worst?  Most people like taking pictures, and that means nobody gives a second thought to whipping out a camera and telling you to smile.  If it's a smartphone without a flash, that's one thing... but some people still like their old fashioned cameras, and being told to smile while being metaphorically punched in the eyeball is just adding insult to injury, in my opinion.  I used to never be able to smile for cameras, in part because smiling was hard, and in part because really, who wants to smile if you know you're going to be hurt?  As an adult, I try to be graceful about being metaphorically punched in the eyeballs, especially around holidays, but it doesn't ever not hurt. 

Fluorescent lights are a whole different kind of suffering.  Did you know that fluorescent lights actually flicker?  They do so at twice the rate of the electrical supply, but most people can't see such a quick change, so the light appears to be uninterrupted.  Except to people who can see it, at which point, well... ever been stuck in a room with a flickering light?  Did it distract you from what you were trying to focus on?  Maybe annoy you somewhat?  Possibly, the longer you sat there watching it flicker, the more annoyed you got?

Yeah, now imagine that's every light in every room in your workplace.  For many children, it is exactly that.  Fluorescent lights are very common in schools.  If the person has auditory sensitivity, they may also be able to hear the flicker as well as see it.  Needless to say, this is immensely unhelpful to learning and focusing.  If you had to try to take notes or learn in a strobe-light room, you'd do poorly and dislike being there, too.

I don't suffer from any of the other types of visual hypersensitivity, but you can imagine, just from reading what they're like, how much they'd get in the way of an average person's life.  If text or objects in your field of vision warp constantly, or even occasionally, recognizing faces or reading reports would become far more tedious, or even impossible.  

Not Listed Above, But Apparently a Thing

What I do have is something that doesn't really fit into any of the categories.  




This is an overly complex line figure.  It is also a psychological test.  You have a person look at this thing, then give them a pencil and have them try to draw one by looking at it.  Then you take it away and have the person draw the figure by memory.  Most people get the general outer shape, then fill in what details they remember.  You can then tell how good their visual processing and attention to detail is.  

When I tried to make this drawing from memory, I drew it clumsily as a series of boxes, with most of the details in the correct places, but the overall shape was off.  I didn't remember how many boxes they were in total, and didn't consider that the whole shape could be construed as "a big rectangular box with some extra stuff on the edges."  I got a decent number of the fiddly details, but the overall reproduction was significantly poorer than average for my age, due to lacking the general structure of the drawing.  I did somewhat better when I was told to try again but instead try to draw the figure as a whole, and then add the details. 

From this, the professional recognized that I tend to see parts of things and not the whole of things, and that it's hard for me to take in lots of visual detail.  This is particularly true when it comes to art and visually complex maps or pictures.  I don't get a whole lot out of most fine art, as such.  I think this probably also explains why it takes me so much longer to see things in video games, and why it was so complicated for me to learn to drive.  In some video games, especially the one I play, you're supposed to be looking for small details in amidst the terrain, and then reacting to them quickly.  This is hard if you have trouble finding those small details amidst all the other details.  Kind of like looking for a very specific bit of hay in a haystack.  

Driving is very visually complex.  There are other cars, road signs, traffic signals, pedestrians, bicyclists, your dashboard, and animals... just to name the things that are relevant to the driving experience.  There's also all the scenery: the buildings you pass, flowers and plants, people in your car, billboards...

Part of learning to drive, for me, was learning where to look for things, and what to look for.  The scenery seems pointless to look at, but sometimes it has road signs, so you can't ignore it entirely.  Not all road signs look the same, particularly street signs in cities and towns.  Then, too, the problem is multiplied by movement.  All these things are passing by, which means you have a limited time to process them before they're gone.  If you missed them, too bad/hope you didn't need that information. 

The precise diagnoses that went with this brain-eyeball communication oddity were Attention-Deficit Disorder (specifically, I was more impulsive than usual when it came to visual processing), and Cognitive Disorder: Not Otherwise Specified (concerns in visual processing and complex visual-motor integration).  These can both be summarized by saying, "She sees stuff weirdly."  

Summary

This week I've described visual processing, what it is and isn't, and most of the ways it can go wonky.  I've also included a description of my particular oddities when it comes to vision, which include light sensitivity but continue right into something not described in my book on sensory processing disorders.  Next week I'll get into the taste and smell senses, which are so intertwined it'd be silly to try to separate them entirely. 

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