Sore Eyes For Sight

I wrote a while ago with an illustrated guide to how the world looks to me. That has changed recently. Two and a half years after having the strokes, I'm not occluding my left eye. The change is more dramatic for observers than for me: it looks a lot better, but it doesn't by any means 'fix' my sight. 

One of the lingering effects of my brain damage has been diplopia, double vision. My problem is not in the visual cortex (where knocks to the noggin can cause double vision), but in the muscles around my left eye. My brain might want to have my eyes line up correctly, but the neurons that controlled eye movement are gone.

Worse, as other neurons take over the tasks of activation, the muscles themselves have atrophied. My left eyelids have not worked for over two years, and I can feel the difference: they are thinner. So, even as my brain recovers heretofore lost function, my body wants to make life difficult.
To make matters more fun, my double vision is diagonal; there is both horizontal and vertical displacement of the images from each eye. (This might make more sense when you know that three pairs of muscles control the movement of each eyeball, not two nor four.) Add in the oscillopsia in each eye, with independent period, and it's a laugh riot.
What has changed is that my eyes are now stable enough that it is now worth correcting the vertical displacement instead of occluding the left eye. I have double vision, still (and, honestly, that sucks harder than I can describe), but it is more-or-less level. It turns out that vertical displacement is a lot harder to manage than horizontal, a fact I would have been interested to learn two years ago.
Experiments have shown that most people cannot tolerate a vertical displacement of 1 but it takes a horizontal displacement of 12* to have the same effect. This helps me understand why the diagonal diplopia was so debilitating; the Fresnel lens I'm wearing corrects for 3 or 4. I don't remember which. The correction is not 1, it's taken over two years to get this far, and the prism lens will not change for another year at best, so whether it's 3 or 4 doesn't really matter.

The downside, since there has to be one, is that the muscles around my left eye are often working harder. That's a good thing! The headaches that ensue, however, are not.
My double vision is better, despite what the expert said, because I have worked on it every day. That is boring, difficult, and imperceptible day by day, but it is necessary. My vision is still objectively terrible, but it is improving.
* No, I don't know what units are being used, but the difference is an order of magnitude. 

Reading For Pleasure

I learned to read when I was 2: my Mom was pregnant with my younger brother and bed-bound for much of the pregnancy. By the time I was 6, I could read a story-book upside-done, to the "little" kids, so they could still see the pictures. I read The Lord of the Rings when I was 10, after being told i was too young; I brought my Dad's volumes to school, since I couldn't take a copy out of the library. After that, I was allowed to read anything I wanted. 

In the same library, before I was 13, I was the first person to read the multiple volumes of the "Tales of 1,001 Arabian Nights" that had been gathering dust for about 80 years. I know, because I had to cut some of the pages (after I learned why some of the pages needed cutting, and why it was OK). 

By the time I was 17, I would re-read The Lord of the Rings in a weekend, though not sleeping much on the Friday and Saturday nights. I didn't know it then, but the escape that book offered was a coping mechanism of sorts. On a long train journey from Bangkok, I read War and Peace; I had to spend a few hours finishing it (and I skipped the second epilogue, which is too obvious if you read the book in one sitting). 

As an adult, I would read light fiction in an afternoon, anything more complex in no more than a week. Interrupting me while engrossed in a book was a good way to shorten my temper, if not make me lose it altogether. Books were a pleasure to be savor end and relished. I was almost never without one.

I've read Dickens, Chaucer and Milton, but not Joyce or Spencer; Tolstoy, Chekov, Solzhenitsyn and Dostoevsky, but not all of their great works; Rousseau, Diderot, and de Sade. I have read reams and reams of 'junk' some of it good, some of it utter crap, but I have stopped reading very few books in my lifetime. I own thousands of books, and have given away or left behind thousands more.

So, I think it is fair to say that reading has been a significant part of my life. 

That all changed when I had the strokes. I've written about and illustrated the visual deficits before, but never really detailed why they make reading so much harder. The diplopia doesn't make a lot of difference, since I'm occluding one eye. However, with One-and-a-half Syndrome it means that now I move my whole head more than just my eyes.

The biggest challenge comes from oscillopsia. Because my eyeballs move up and down rapidly, it has become very hard to read a longer line of text unaided. Larger text (available from libraries or eReaders) is less useful than greater leading (not usually an option), although it is a bit better. Small, dense print is effectively illegible.

Unfortunately, reading is now much harder work than it used to be.  Before, I might comfortably read a quarter of a book at night, now I'm lucky to read a chapter before becoming too tired. Audiobooks offer a solution for new books, but my pleasure has been in the reading itself, and hearing someone else's voice interpret text is no fun.

With either an eReader or an audiobook, there is also the problem of the thousands of books I already own, and can't afford to replace in other formats. Reading one of the books I've kept allows me to experience the world in a particular way, to enjoy a certain tasty idea or be thrilled by crunchy repulsion again, or just to find something new there that I hadn't perceived before.

The difficulty I have with reading is all about the physicality of the process. It will improve with time and practice. For the moment, though, it pretty much blows, and I've seen no way to restore what was lost. It's one of the areas where my stubborn insistence on recovery over compensation costs me most. TV isn't as good. 

Eighteen Months

It's odd that my SSDI assessment is today, exactly 18 months since I had a series of strokes. I often play down the difficulties I have - I don't want to be a whiner - and I'm trying to concentrate on the ability part of disability, inspired by this year's Paralympics amongst other things.

Today, though, I have to look medical orthodoxy in the eye and believe its depressing conclusions: I won't get any better from here. I think that's not true, but I am aiming to give orthodoxy the finger by continuing to improve, and in the meanwhile it's better not to be deluded (as they might think). So, reality check update.

Mental
As I will repeat to anyone that will listen, there is no sign of cognitive impairment. I think there is some damage, though, but I was smart enough before the damage that it's not measurable afterwards. It isn't major, but I am just not as sharp as I was. Maybe that's just because my brain is busy. Depression has been more significant since the stroke. It's hard to see a future being this crocked. It will be somewhat easier if the SSDI is approved because then I can make getting better a full-time occupation.

Facial
The palsy is slowly lifting, but the left corner of my mouth remains stubbornly inert, which means lopsided smiling and I have to be careful laughing and eating. I suspect some friends try to make me laugh when my mouth is full, but I'm OK with that. Bastards. I can just barely close my left eye, at night my eyes roll up a bit to get darkness.

Visual
This is the worst area, with least improvement. Specialists think there will be none. I believe my double vision is getting better, but it is glacially slow, and I still have double vision. I also have One and a Half Syndrome, and that may never go away, especially the nystagmus in the right eye. Harder to see from the outside, but pretty obvious to me is the oscillopsia, which is best illustrated in my post on how the world looks to me. It still looks like that.

Balance
I wobble and stagger, and occasionally fall down. I wrote about falling outside, which was the first time I went arse over tit outside in New York City, but a couple of weeks ago I fell in my own apartment, and every day I stop myself falling through conscious acts. I sway forwards and back without any apparent rhyme or reason when I don't have anything anchored (a hand or my ever-present stick). Honestly I can't tell if my fundamental ataxia has improved or as I suspect, my ability to handle it..

Tremor
The dysmetria continues in my right side. You should see me try to pick up dice. Or a pencil. It's pretty funny. Except that it isn't; I still can't carry fluids in my right hand without spilling them, eating is an adventure, cooking is a challenge, and folding clothes is a punishment worthy of the ancient Greeks.

Weakness
There's no doubt that I've got stronger. When I did the standard neurological test of squeezing pairs of my doctor's fingers, my grip is pretty strong. But the test is useless at determining how strong I was before, particularly relative to the left side. That's where much of my problem lies with strength, that, the tremor and the fact that stabilization muscles have got weaker.

So, that's the month's round-up of woes. It doesn't cover where I think I've improved, and nothing really explains how tiny the incremental improvements are. But I don't recommend having a stroke to find out. I'm about to set off for this assessment; I will probably be very early, but I'm still pretty bad at estimating travel times, so I hope the waiting room is nice.

How the world looks to me.

Normal vision

Since pictures substitute for words in many cases, I thought I would try to illustrate how I'm seeing at the moment. I'll build up separate images with each effect of the brain damage, so you can get an idea of how things look to me. I'll stick to the images that my eyes are sending back to my brain, which perceives the world slightly better, but works poorly with text.

First, here's the image I'm going to work from. Bear in mind that most of you would see this in 3D, but I don't. It's the cabinet in my living room that's full of games and game books. Notice that it's not hard to read Hoity Toity or Goa, and many of you will recognise Settlers of Catan.

Myopic version

I have been myopic (short-sighted) for over 30 years, so without glasses, the view would be blurred. I am very myopic so things are very fuzzy. Not so bad that my glasses look like the bottoms of milk bottles, but headed in that direction, for sure.

Of course I wear glasses, and used to wear contact lenses, so the world is not so blurry until bedtime, but since the strokes, I have had double vision (diplopia) which confuses things. I have diagonal diplopia, which is oddly more confusing than just horizontal or vertical displacement. Because my diplopia is rooted in the coordination and function of my oculomotor muscles, the muscles that move my eyeball, rather than in the visual cortex, the displacement is not fixed, it swims around.

Diplopia version

I also have 1.5 syndrome, which for our purposes here means that the displacement differs depending on where an object is in my field of vision. The syndrome has affected my left laterus rectus primarily, but some of the other muscles too, so the doubled image is both translated diagonally, and slightly rotated. The image to the right is a reasonable approximation to what I would see wearing glasses, almost. Read on for more wrinkles! It's not quite accurate because my image manipulation skills are not mad enough to convey the contention of the two images. You can clearly see the Goa there, but the picture doesn't give a sense of the other Goa wanting to be read first and foremost.

To manage the diplopia by reducing my visual signal to a single useful image, I have an occluding filter on the left lens of my glasses. Or, in English, I have a disc of translucent plastic that sticks to the inside of my left lens and makes it all blurry. Peripherally, my left eye has the benefit of my glasses without the filter, which should be of some use looking down, but because of the 1.5 syndrome, is not much cop on the left side. Dashing as a patch might make me, keeping my left eye essentially uncovered like this keeps it moving in (broken) concert with my right eye, and can only help with recovery. The effect of the filter is that I see something like the image below.

Occluded version

The irony of making one side of my vision so useless that my brain ignores its input is not lost on me. It's not always effective, either; sometimes, especially when I am tired, my brain seems more interested in the garbage coming from my left eye than the more useful stuff from my right.

The final, and frankly most debilitating visual deficit I have is oscillopsia; my right eyeball moves up and down a little, rapidly and regularly. As the size of the movement is usually at least a line of regular text at my comfortable reading distance, this makes reading difficult. It's also better or worse variably, but it's never better than below in terms of distance moved. The jitter is also quite a bit faster in my eye than in the animation.

Of course, it's not the eyes that do the seeing, it's the brain. What I've tried to illustrate is what  my eyes are sending on to the brain. What I actually perceive has changed over the last seventeen months, so I'm better at seeing a steady field of view, especially for rooms that are familiar. It's worth noting that I'm discarding the information from one eye completely, so I don't have binocular vision. I can't tell how far away things are, how fast they are moving, or how flat they are. Sidewalks are exciting! One of the notable effects is that the brain evidently retains a working model of the world, and uses that when there's no depth or distance information available: I can reach for a glass that I put down recently, but if you move it, I will miss.

Oscillopsia version

I seem to have learnt that the world is not constantly shaking, so the oscillopsia is usually (but not always) ignored in familiar spaces, but it is in full effect when I try to read. One trick I have used to read signage or subway advertising and the like is not to try to read a line of text from, say, a poster, but to allow the image of the text to be assembled coherently in my brain, and to read it from there. This trick is fiddly to execute!

One other thing I have learned from my ocular odyssey is that I infer a lot of the actual text in many novels; the word choices are so often obvious that I don't actually read them, but assume the word given the context. This is less easy with non-fiction, and I find any reading tiring regardless.

EDIT: Over on Google+ a friend was asking how I could even prepare these images given the way my eyesight is at the moment. I've had longer for my brain to get used to the way my eyes behave, I know what my eyes do, and I'm pretty familiar with my computer. The image manipulation is fairly simple. It still took more than a day, mostly because I was tired. Looking at unfamiliar things is most like the last image. 

Later, I likened it to looking at things from a very rattly moving vehicle. Distance stuff is easier and more solid, because the brain is used to the eye moving rapidly over near things and assembling a distant image. That image is not always correct, because the brain interpolates things (one of the reasons that a lot of eye-witness testimony is bollocks), and sometimes it fills in the gaps with things that should or might be there, but aren't.

Nearer stuff is impossible to perceive at a glance because I am having to do pretty much the same thing for near vision as the brain does for distance perception, and that's not instantaneous. It takes me enough time to check cross streets for oncoming traffic that I might as well just wait for the lights. I almost never jaywalk alone. Similarly, as I'm typing, I know what words should appear, and in what font, so my brain has an easier time of adding new words to a page of typing. Reading a previous paragraph, though, sets me back again. END OF EDIT

As usual, questions are welcome!

Neurologist Visit

Yesterday, I took a trip up to London to see a consultant neurologist with a specialty in dealing with vision. I'm due to go up to the regular got-referred-in-early-December eye clinic in two weeks' time, but when I got the appointment for that clinic, nearly a month ago, I was desperate to see someone about my sight, and so I shelled out to see this guy privately. He's one of the pre-eminent neuro guys around, all the people at the eye clinic will know him, his name was given to me back when I was in hospital in the US, so he's definitely the right guy to go see.

Except I don't believe him, and I think he's wrong, and while I don't for a second feel like I wasted the money (on the order of $500, thank you disability allowance), I got more out of seeing old friends and teachers from drama school in the afternoon.

He was professional, thorough and on the ball, and thought that I'd probably seen all the improvement in my double vision that I was going to. The one and a half syndrome might improve. The oscillopsia (vertically wobbling eyes) could maybe be treated with a drug... that would have a deleterious effect on my stability, making it challenging at best. My balance issues are likely unrelated to my vision, but daily balance exercise for ever will help. So:

• Diplopia - tough shit, carry on.
• One and a half syndrome - tough shit, carry on.
• Oscillopsia - there's a drug, it sucks, probably tough shit, carry on.
• Balance - tough shit, carry on with your walking stick.

Also, since the one and a half syndrome is so rare these days would I mind coming up for a half day with some students... they'd reimburse travel. Of course.

Now, I'm in no rush to dismiss the expert opinion of an eminent neurologist (I'm still going to, it's coming), and I'm genuinely happy to have someone pay for me to go up to London and amuse medical students for SCIENCE, and I may just be in deep denial about the whole thing, but I respectfully decline to take his word for it, for two major reasons:

First, he quoted to me the neurological canard about there being negligible progress after about six months. Since I have seen walk into my hospital room (with a stick, and with difficulty, but walk) someone who could move only the toes of one side at six months, I consider this, on its face, false.

Second, I continue to see change and progress in my vision. Slow, for sure, and inconstant, but I am certain that the double vision is gradually improving, as I mentioned a week or so ago. My left eye can look slightly to the left of the midline which says either my left LR is weak but working, or the diagonal muscles are working hard to try and compensate.

Underlying my dissent from neurological orthodoxy is a question that remains unresolved for me, mostly because I'm not asking it hard enough, or of the right people, or because we just don't know. It is this: how are the nerves and muscles of my eye different to all the other damaged nerves?This is crucial. My eyeballs themselves are fine, it's the nerves connecting to and controlling the extra-ocular muscles that are damaged (or dead) and must be worked around. Going to the gym, as well as making me fitter and stronger, has improved the musculature, control and nerves of my right side.Why should it be somehow less effective to work the the muscles of the eye? Show me the science.

More nebulously, and rather irritatingly foo-foo-ey, I am arriving at another conclusion about our neurology and the brain's rather amazing ability to recover function: believing we can or should heal some part of the brain, or re-learn some useful skill makes it possible to recover that function or skill. I can't be doing with some of the deficits I have, and I'm determined to eliminate them, and I think that that choice, that mental direction, influences the actual neurology of recovery. Again, I want evidence beyond the anecdotal, and my personal, and again I have arrived at a question I would love answered:

Is there a significant difference between the expected and actual outcomes predicted and observed by neurologists when treating stroke patients as compared with treating victims of external brain injuries. Do we have higher expectations of, say, Gabrielle Giffords, who was shot in the head, than we do of a stroke sufferer, and does it make a difference?

Seeing From Eyes to Mind

Many years ago, I was taught in biology class that, while the eyes register visual stimuli, it is the brain that actually sees. I dutifully learnt the fact, but didn't ever truly believe it, or rather didn't really understand it. Experientially, as someone growing up with gradually worsening myopia (short sight), it seemed that my eyes were doing all the work, and I didn't comprehend how the brain was really involved.

Sure, I understood about binocular vision and depth perception and all that stuff, but it wasn't until I damaged my brain and suffered some visual problems as a result that it became much clearer. I now understand better than ever that the eyes 'merely' process visual information, the brain sees.

To explain how this has worked for me, I'm going to bore you with my current deficits again. As you may have gathered, 'deficit' is the charming circumlocution used to destigmatise phrases like 'brain damage' and 'disability' that nevertheless makes it pretty clear to me that I am less than once I was. While unfortunately I recall what it was like not having deficits, fortunately I also stand to recover the damage done; I prefer to focus on recovery than damage.

Anyway I have two or three deficits to contend with at the moment: double vision (diplopia) and one and a half syndrome, which may be the cause of the third, oscillopsia. My diplopia is diagonal, with the left eye image up and to the left of the right eye image. The oscillopsia I've had in both eyes, and is worse first thing in the morning, or late at night if I'm tired. I'm generally worse in all respects at those two times: Starting the day with a mug of tea seems to help.

One and a half syndrome is sufficiently rare that it causes excitement bordering on glee when experienced stroke neurologists encounter it. I'm often the first case they'll have seen outside of an exam question, and have in fact been asked if I would mind being an exam question (I don't mind at all: I'm game for anything that involves students in neurology and all research studies along the way). The wikipedia article describes the syndrome well, and I won't repeat that here, but you might want to have a read: one and a half syndrome.

What it means from the inside is that my eyesight is kind of screwed for the time being.

The most debilitating effect has been the diagonal diplopia. Soon after my stroke I found that it was practically impossible to operate with both eyes uncovered. My brain could make almost no sense of the competing visual fields offered by my eyes. This was quite peculiar, because although at a higher level I am able to recognise intellectually that I am only holding up a single right hand, my brain cannot rationalise the two hand images into a singular binocular image and insists on 'showing' both. The data one part of my brain is receiving can not be processed into the type of image another part of my brain is used to receiving, so it just gives up and passes on the two superimposed images.

The vertical offset in the diagonal plays havoc with my balance. Although proprioception is the lion's share of balance, there's a considerable visual component as well, and having one eye tell me that the floor is this way, while the other assures me that, no, the floor is that way is a surefire way to keep falling over. My proprioception was shot, too, so all in all the most convenient way to help my brain pick one image over the other and stick to it was to occlude one of my eyes. Since my left eye is the one that doesn't track to the left, and had developed a squint (which I thought was unspeakably ugly and made me more likely to be treated like a fool), I covered the left lens of my glasses with a special frosted covering, and tried to get on with it.

Operating with only one eye is more challenging than I had thought. I had an idea that it would be awkward, but had no idea quite how bad. My undying admiration goes to my friend with a glass eye. I have no idea how she makes everything appear so fluid and easy. Regardless, lack of depth perception has been unpleasant in many ways, and I'm reasonably confident in saying you will have no idea how unpleasant it is until you try it while your balance is already off.

Occluding my left eye made the diplopia manageable, so I can do things like use my laptop and read a book at all (slower, of course, but luckily I can still read), but it highlighted one of the features of one and a half syndrome: nystagmus in my right eye. When I look to the right, I'm able to do so with both eyeballs, but the right eyeball flicks rapidly to the center and back again. To add to this is the experience of oscillopsia: When I focus my gaze on a single point, my eyeballs wobble up and down a little..

These deficits are what has made it very clear that my brain is doing theseeing part. Most of my deficits are in fact neuro-muscular: There's nothing wrong with my eyeballs that wasn't wrong with them beforehand, instead it's the connection between my brain and my left lateral rectus that's been most clearly damaged (the VIth cranial nerve), and my brain's fine control over the whole extra-ocular musculature that has also suffered. 

To form a binocular image, the brain instructs the eyeballs to keep a single object focused on the macula, and combines the data that the two eyes present into a single image with depth This is something we learn as babies: Watch a six-month-old's eyes wander around and the focus sometime. Lacking the muscular control to move my left eye so that it focuses on the same spot as my right (remember the squint I mentioned?) my brain ends up with the double vision. With one eye effectively taken out of the picture, it should have been plain sailing, but it wasn't.

It soon became apparent to me that my right is moving involuntarily. Not much, but if I focus on one word on a page or screen, the motion is obvious to me. Despite this, though, I perceive a largely steady, static world around me. My eye is jiggling around a bit (not enough for truly comic effect, although I do have moments of feeling like Mad Eye Moody), but the world is still. This is the brain seeing. In effect, it's learned to recognise the jiggle as a kind of scanning of the world, and maintains a static image for me to use, because the alternative is chaos.

In effect, my brain is discarding the fuzzy occluded data from my left eye, then applying Occam's Razor to the data it's getting from my right eye, and providing me with that filtered perception. It makes a lot more sense that the world is not constantly jumping up and down, so my eyes' raw data has been subjected to reason at a very low level.

All of which is my own understanding of what's happening in my brain and eyes. Neurologists and ophthalmologists who actually want to talk to stroke patients about their vision are few and far between, and their message has been consistent on both continents: wait four to six months, eye problems with stroke usually clear up on their own. Given how terribly debilitating the visual problems I have are, and how depressing the apparent lack of change in my vision has occasionally been, it's a little surprising and a lot disappointing how little information was available to me. I guess four months doesn't seem that long when you're a clinician looking at a long stream of stroke sufferers ready to start their recovery (or decline), but it has felt like an age to me.

Happily, a few weeks ago I started to suspect that the diploplia was steadily resolving, and that seems to have continued. Like everything else with stroke recovery after the very early stages, it's abominably slow, but I think it's real. The difficulty is that my eyes don't get a lot of time to practice looking at stuff and being wrong and being corrected by my brain: That feedback loop that's been unused since I was a babe in arms needs some exercise. Fortunately there are two times when I take my glasses off, and I'm used to being unable to see (really strong myopia): in the shower and in the pool.

In both cases, I'm usually thinking about something else, so my eyes have free rein to do whatever they want; I put very few demands on them. In the shower, I'm focused on the mechanics of getting clean; in the pool, I'm concentrating mostly on the form of my breast stroke and being as even as possible. Hitting the end of the pool isn't really a problem. So it looks like, with the swimming in particular giving my eyes a bit of a workout, and with the exercise I've been forcing my extra-ocular muscles to take, the double vision is on a path to recovery.

The one and a half syndrome may be with me for good, but the squint is gone, my left eye is tracking in tandem with the right (mostly) now, and itseems to track to the left past the midline. Which is either a positive sign that I may recover from the syndrome, or evidence that the extra-ocular muscles are compensating cunningly. Finally, I have hope (but nothing else) that the oscillopsia is related to the double vision, with both eyes trying to find a common focus, and so far failing. If that's the case, all to the good. If not, well it could have been a whole lot worse.