Look twice and then again: dealing with one-sided visual inattention

Another frustrating symptom I had to deal with was an inattention to things that were on the right, the blind side of my visual field.  I found that this is called one-sided visual inattention or neglect.  It is a common problem after a stroke. It can range from mild to very severe.  Luckily my right-sided inattention was mild.  Still it was frustrating.  It took time and energy to correct.  And most importantly, I could not drive until it was corrected enough to make driving safe.

At first I had so many disturbing visual symptoms that I did not notice the inattention.  But once my visual field cleared and expanded, and the hallucinations became smaller and then disappeared, I noticed that I had some trouble finding objects, if they were on my right side.  I would walk by the desk looking for a pen that I knew was there and not see it. That was puzzling, because by that time I could see quite well into the right side of the visual field.  The same thing happened when I practiced Eye-Search.  When the stimulus jumped to the right side, it took me longer to find it than when it was on the left side.

I started observing myself and experimenting and I developed the following hypothesis:  my brain processed what was on the right side of the visual field slower than what was on the left. However, my brain did not know this. It had developed a habit of looking for something for a certain number of seconds. If, within that time interval, it did not see what it was looking for, it decided that the object was not there.  

It became obvious that I needed to teach myself to look longer and more persistently when searching for things on the right. This is a tedious and tiring undertaking.  It involves forcing the eyes to scan through the "blind" side. And it involves being constantly aware of the attention deficit and compensating for it, by looking repeatedly and longer on that side.  And the hardest part was not the doing of it, it was "remembering" to do it.  

I had to train myself to look twice and then look again, until I found what I was looking for. What I used to do naturally before, I had to do intentionally now. 

• When walking, I practiced scanning consciously and repeatedly the right side of my visual field. 
• When reading, I practiced looking at the end of a sentence on the right first, before I started reading from the left. 
• When I was being driven around, I practiced looking and noticing what was on the right side.  
• Whatever I was doing, I kept telling myself, look to the right, look to the right, notice what is there, remember what is there.  

I was helped in improving and tracking my right-side "speed of detection" by playing online "Brain Training" games on Posit Science's BrainHQ website. (In another post I will describe them in detail, but you can click here to access their website). 

I focused on those that aim to improve one's brain speed. One of these games is called Hawk Eye. It involves presenting a group of birds for increasingly shorter time intervals.  One of the birds is slightly different and the player has to find it.  In the beginning, when the "odd" bird was on the right side, it took me much longer to detect it. Slowly my performance improved and I was able to move to more difficult levels of the game.   

Over time the "looking to the right" became more automatic and the finding of things slowly faster.  There is still a difference in the speed of detection of things between the two sides, but it is getting smaller.

An article on visual inattention by the British and Irish Orthoptic Society (1) notes that visual inattention is more a disorder in "looking" rather than "seeing".  Treatment involves getting the patient to look into their affected side. This is exactly what I found that I needed to do.  

Here are links to pages with information about visual inattention or neglect.

1. The British and Irish Orthoptic Society offers a very informative patient leaflet:  Visual Inattention after Stroke. (Click here)

2.  The Hemianopsia.net website has an excellent page on visual neglect and its rehabilitation. (Click here)

What happened to my brain and I can't see well?

I have been very curious about what happened to my brain that resulted in  right homonymous hemianopsia. I wanted to know the exact location of the injury caused by the stroke. I felt that my right eye was not working well, yet I knew that both eyes could not see the right side of the visual field. I wanted to see a picture of what was going on. 

 Eventually, one of the neurologists I saw looked at my MRI and drew a rough picture of the brain and the location of the stroke for me.  His picture inspired me to search online for "maps" of the brain that showed areas of damage to the visual pathways and the resulting visual defects.

A Google search showed me a variety of images and drawings that have to do with Hemianopsia.  I chose two drawings to include here:

The first one comes from a website called "StudyBlue.com"  that offers digital study tools to students.   It is part of the neurology notes of Jared Rickert, a student of osteopathy at  Still University. (Click here to see his notes).

I chose this diagram because it is very simple and clear.  It shows a brain that has been sliced at the level of the visual system.  The eyes are in front. Optic nerves come out of each eye.  The nerves from the right side of each eye carry information about what is on the left side of the visual field.  These nerves go around the right side of the brain all the way to the visual cortex on the back of the brain.  The nerves from the left side of each eye carry information from the right side of the visual field.  These nerves go around the left side of the brain back to the visual cortex.  That is the reason why someone with an injury to the left side of the brain, like myself, becomes blind to the right side of the visual field.  

The black lines with the numbers next to them represent damages or "cuts" to the nerves from stroke or brain injury. Each "cut" is numbered and corresponds to a particular visual defect that is drawn in the numbered circles to the right.  The dark area in each circle is the area that is blind.  

A person who has had a field of vision test and was diagnosed with a visual field defect, can look at the picture above (or the one below) and find in a general way where the damage that caused the defect is located.  The drawing above  shows what happens when the damage is on the right side of the brain, which affects the left field of vision.  When the damage is on the left side of the brain, the right field of vision is affected in a similar way. 

• To see and explore additional drawings of visual field defects and other Hemianopsia images from Google Search, click here.
• A chapter on Visual Fields by Robert H. Spector in a textbook on Clinical Methods has a very good medical description of the location in the brain of particular field defects and their consequences. (Click here  to read the chapter).

What the world looks like with hemianopsia

In the beginning right after the stroke I found it difficult to describe what the world looked like out of my eyes.  People could not exactly understand my visual reality from the verbal descriptions of my visual field.  Once I could see and read better, I started looking online for pictures that would approximate what my vision was like after the stroke.

I eventually came across a website, Forkintheroad.com, that makes goggles simulating different types of visual impairment.  The goggles are meant to be an educational tool for helping health care, rehabilitation and education professionals, care providers, and friends and family better understand some of the abilities and limitations brought on by visual defects.

The picture above is a simulation of what the experience of Right Homonymous Hemianopsia is like.  The visual field is blurry on the right side, some objects are partially visible through the blurriness and some are not at all.  My hemianopsia was slightly different in that I could see the lower areas of the right side. However, when I looked at people's faces or at the page of a book, the right side was blurry just like this picture shows.

The Fork in The Road website offers goggles and pictures for many different types of visual problems.  (Click here to link to the  website).

Exercising the eyes in the natural environment

 Computer based scanning exercises are great for retraining the eyes to scan.  However, the range of eye-movements they require is limited to the size of the computer monitor screen.  The visual field in the real world is much wider.  To view it and scan it properly the eyes need to practice in real world settings.

The Hemianopsia.net website points out that in treating hemianopsia...

"The first step is to train the patient to make large exploratory eye movements (saccades) into the field of loss... After the large saccades are developed, smaller more precise saccades can then be trained. The third step, we recommend is to improve speed in real world situations. The fourth step is to attempt to integrate the scanning into real world activities". (Click here for the whole page.)

Here are some exercises I did that I have found helpful:

1. To expand the scanning arc of my eyes (make larger saccades), I did slow eye rolls, up and down, left and right, and all around, while "looking" and "paying attention" to what I saw.
  

2. Every time I entered a room I scanned it from left to right and back again. This helped me become more aware of what was in front of me, as well as the areas that I could not see clearly. 

3. I put small bright balls at the corners of window sills across from my favorite chair and kept moving my eyes from one end to the other.

4. I practiced looking for and finding things that were in the blind side of my visual field.  I placed objects on the right hand side of then dining room table, of the kitchen counter, of my desk, and each time I entered the room I looked for them.

5. I also played lots of computer games and puzzles that aim to improve vision.

Resources

Website with eye exercises 

Livestgrong.com (Click here)
Stroke-Rehab.com (Click here)
Hemianopsia.com  (Click here)

Websites with games and puzzles for improving vision

Eyecanlearn.com (Click here)
Visionnorthwest.org (Click here)
Edhelper.com (Click here)

I can read again!

 Possibly the most distressing and frustrating symptom of my hemianopsia was that I could not read.  

When I tried to read after the stroke, I got dizzy.  The right side of each page was blurry and darker.  The other half seemed to contain fuzzy letters and words that did not fall into an orderly sequence, they required tremendous effort of concentration to see and decode them.  I could not read the newspaper, books or emails, street signs, freeway signs, or food labels.  I worried that if I did not recover my ability to read I would not be able to live independently and I would never be able to drive again.

This fear gave me extra motivation to try and correct this problem. The ophthalmologist and the two neurologists I consulted did not seem interested, concerned or trained to deal with my reading problems. The optometrist I was referred to did not do vision therapy with adults.  I was left to my own devices.  

My initial efforts to read were tedious, frustrating and time consuming. I was not able to read books or magazines because the letters were too small. I did all of my reading on my iPad or the computer, where I could enlarge the size of the font so that I could see them clearly.

Initially, if I held the iPad in its "usual" position I could not see half of the screen and half of the text.  I experimented and found that if I tilted the iPad upwards on the right about 45 degrees, I seemed to bypass the blind area and see the words on the right side more clearly.  I found that easier than tilting my head to the right for long periods of time. 

For several days after the stroke I could only read in a letter by letter fashion. I was sounding the letters in my head like a first grader.  In addition, because of the visual defect I could only see the left half of each word, not the end.  To see the end I had to move my eyes or head actively or tilt the iPad, and even then I could not see a word as a whole. During that period reading was slow and difficult.  But I persisted because I wanted to give my eyes a chance to start reading again.  Increasing the font to nearly fill the page, I read and wrote emails, and read an ebook by putting the letters together to form words. 

And I had the visual hallucinations I mentioned in my previous post. Even when I could see the right side of a page by tilting the iPad, it was filled with moving shiny designs that would appear and disappear. The designs obscured the text.  I could see the letters and words but with lots of distortions. 

Ten days after the stroke I had the first scalp acupuncture treatment and the visual terrain changed. My visual field expanded to include more of the missing right side. The blurriness of the right side cleared a bit.  My eyes started to work better together. Upon returning home, I found that I could see and read a little bit better, that the letters combined themselves into words with less effort.

After the second treatment, I was able to see whole words rather than an aggregation of letters.  Reading was still effortful and tedious because the decoding of these words was very slow. After the third treatment, when I was being driven home with acupuncture needles in my scalp, I noticed that I could read some street signs and freeway signs while the car was moving. That was a very exciting development. After the fourth treatment, I could read longer freeway signs out of the moving car with greater ease. I went to the grocery store and scanned the shelves and read the labels without getting dizzy.  Shopping was slow but very satisfying.

One of the problems that people with right homonymous hemianopsia have is the way their eyes move when they read words. These eye movements are called saccades and hemianopsia seems to disrupt them. 

I have found a couple of interesting videos online illustrating the differences between normal and hemianoptic people when they read 5 words.

Timothy Hodgson, Professor of Cognitive Neuroscience at University of Lincoln, UK, has posted on YouTube two videos: one showing what the movement of normal eyes is like when reading 5 words, and one showing what the eye movement of someone with right homonymous hemianopia is like reading 5 words. The captions below each video are Dr. Hodgson's.

Here's an older control subject reading aloud sequences of 5 words slowed

down to half speed for comparison with the accompanying video of right 

hemianopic stroke patient doing the same task. Note that here there is

typically just one fixation per word. (This playback was captured from old 

Mac software via VHS tape(!) so apologies for poor quality)

   

Eye movements recorded from a patient who suffered a stroke leading to partial 
loss of vision on the right, reading aloud sets of five  words. Note relative to the 
other video showing reading in a healthy subject this patient is struggling to read 
across the five words, making many more fixations with reading ability severely impaired.

There is a lot of information on the web about the reading problems that follow a stroke and their rehabilitation. The inability to read is a condition known as hemianopic dyslexia or hemianopic alexia.  Unfortunately, at the time when I needed this information the most, I could not really read it.  So I had to invent my own rehabilitation tricks.  I started by noting what I was doing that was not working and correcting it.  

Even with the contribution of acupuncture, which seemed to accelerate the healing of the visual processing areas of the brain, reading required lots of effort and practice. Reading and understanding sentences is different from reading single words. I had to make a conscious effort to move my eyes from the beginning of a word to the end of it, so that I could take it in as a whole. I had to practice moving my eyes to see the complete sentence. 

I noticed that when I read words, I would first look at the beginning of each word and because of the visual defect I would miss the end. I started practicing focusing somewhere in the middle of each word, so I would see it as a whole. I later discovered that optometrists recommend that a patient should practice looking at the end of words and offer exercises to teach people that.  I have added a link to a page from the Hemianopsia.net website that describes optometric exercises and aids for reading rehabilitation. (see #5 in the references and resources) 

Sometime after the fourth acupuncture treatment, when I could read whole words, I discovered that if I focused my eyes about 10 to 20 degrees to the right of the midline of a page, I could see the whole page.  Using this strategy I could see the whole screen of my iPad!  I could see the whole screen of the television!  I could see the whole front panel of my car!  I started hoping that I could drive again.

What would I have done without an iPad and a computer?  I don't know.  I used the iPad as a reading aid and trainer. In addition, during the weeks when I was unable to read the newspaper, I listened to Audible's daily summaries of the New York Times.  I listened to several audiobooks.

I used the tiles of its screen to test my visual improvements.  In the beginning I could only see the tiles on the left side of the screen when I focused my eyes in the middle.  Then I started seeing the right side tiles as well.  Now, when I focus in the middle, I can see all the tiles on the screen but 3.  

I found and used iPad applications that test the visual field.  And, once my visual processing improved, I started playing games, and brain games that improve vision.  I will describe them in another post.  

A useful discovery was the online therapy program Read-Right for people with hemianopic alexia. It was  developed by the same people at the University College London Institute of Neurology, who created the Eye-Search therapy I described in a previous blog.  The video below describes the program.



Using Read-Right, I started reading an excruciatingly boring Agatha Christie mystery, whose text was being scrolled at the top of the screen.  After about 9 hours of reading practice, I was able to read at nearly the fastest scrolling speed of the program. I was about three quarters into the book, when I stopped using the program because my reading  finally felt fast and effortless.

Through the combination of  acupuncture and exercises that retrained my eyes to focus and move differently,  I am now able to read without eye strain and with increasing speed.  I do not need to increase the size of the font when I am using the iPad or the computer.  I am able to read print books and the Economist, a magazine of small print and much information. I was able to watch foreign movies and read the subtitles 45 days after the stroke.

Once I could read, I searched online for information about reading problems related to hemianopsia.  I found many  research papers and textbooks describing the reading problems of hemianopic patients. I have added links to several of them at the end of this post. 

Here's what I learned from them:

In Europe the condition is called hemianopia and in the US hemianopsia. Both terms refer to the same visual problem.  There are many different kinds of hemianopsia, depending on the location of the brain injury.  Each type has different reading challenges. Right homonymous hemianopsia, the kind I have, disrupts the motor preparation of reading saccades (eye movements).  Patients adopt inefficient eye movements and inefficient eye fixations, which make reading slow and frustrating.  Rehabilitation involves retraining fixations and saccades, which is what I did using my own observations and intuitions.

It is now 3 1/2 months after my stroke.  As I am typing this, I can see the whole screen of the laptop.  I am aware that I can do this because I am fixating my gaze a bit rightwards. If I look at the center of the page, I can't see a small chunk of text on the right side.  This chunk that I can't see has been getting smaller.  I can scan lines of text effortlessly and read at a very good speed.  

I still have to actively move my eyes to look on the right side of the keyboard to find the delete key. I still have a kind of right-side inattention, called neglect.  I will write about inattention in a future post. Some of the things I used to do naturally before the stroke, I now have to do intentionally.

While writing this post I realized how much work I have put into rehabilitating my reading capacity. I seem to have reached a plateau right now. I am still working on making my vision more efficient, but for the time being I am quite satisfied with what I have accomplished.

References and resources

1. Impaired reading in patients with right hemianopia. (click here to read abstract)

2. Page on Homonymous Hemianopia on the website of the North American Neuro-Ophthalmology Society. (click here to read)

3. Article posted on the Hemianopia Society website: "Patients with hemianopic alexia adopt an inefficient eye movement strategy when reading text". (click here to read)

4. Chapters on acquired visual defects in a textbook of Neuro-Ophthalmology by Joel S. Glaser. A very scary book describing the wide range of visual disasters that can befall stroke victims (click here to read on Google Books)

5. Excellent resources with exercises developed by optometrists at The Hemianopsia.net website: Reading problems after Stroke or Head Injury. (Click here)

My visual hallucinations and Dr. Charles Bonnet

 Once my vision became better organized and scanning the environment felt normal, the symptoms that interfered most with my seeing what was there and kept me from driving were the visual hallucinations. 

Visual disturbances were the initial symptoms of the stroke. They came together with migraines, but continued after the migraines stopped. In the beginning the right side of my visual field was covered by a chess board with yellow and black rectangles.  Then the chessboard was replaced with pretty decorative designs of different shapes and colors. Sometimes I saw scarves or clouds moving in the wind.  

Then I started seeing people.  Faces would pop up here and there, or whole bodied people.  For a while they were stationary, appearing next to me or across the room. For a couple of weeks they were moving towards me, or across the living room in front of me, or crossing the street in front of the car.  Whether they sat or moved they all turned, looked at me and smiled. Their presence felt very reassuring.  

After a couple of weeks of smiling people, the visions became smaller in size.  I started seeing dogs and cats crossing the room, or sitting in different places in the house. In the garden I saw butterfies and birds.  Then the designs returned, but they were smaller and less obtrusive. When I was reading little mushrooms or elves or colored shapes would pop up on the right margins of book pages. Sometimes the images would move away from the text, but often they would cover it and interfere with reading.  When I moved my eyes looking around I would often see small shapes or colored designs that would appear and then dissolve.

The neurologists I consulted were uninterested and uninformative about these symptom.  Again I had to resort to Google.  I Googled "Visual Hallucinations" and found out about Charles Bonnet.

Allan Bellows has written an amusing and informative article on "Chuck Bonnet and the Hallucinations" in the website www.damninteresting.com.

Here are some excerpts:

In the year 1760, a Swiss naturalist named Charles Bonnet became concerned when his grandfather Charles Lullin began to experience a parade of "amusing and magical visions." The eighty-nine-year-old Lullin was being visited by visions of people, birds, carriages, and buildings, all of which were invisible to everyone but him...

...Bonnet's grandfather did not demonstrate any other signs of marble loss, in fact he seemed quite sane aside from the vivid hallucinations. Moreover, the elderly man was keenly aware that the strange sights were all in his mind. Bonnet cataloged his grandfather's curious circumstances, and over time the condition he described came to be known as Charles Bonnet Syndrome, or CBS. Numerous similar cases have been recorded in the decades since, and though it has long been regarded as a rare disease, recent evidence suggests that it is much more widespread than previously believed...

...For those stricken with Charles Bonnet Syndrome, the world is occasionally adorned with vivid yet unreal images. Some see surfaces covered in non-existent patterns such as brickwork or tiles, while others see phantom objects in astonishing detail, including people, animals, buildings, or whatever else their minds may conjure. These images linger for as little as several seconds or for as much as several hours, appearing and vanishing abruptly...

...The exact cause of Charles Bonnet Syndrome is not presently known, but the popular theory suggests that the brain is merely attempting to compensate for a shortage of visual stimuli...

...One of the most thorough studies of the phenomenon was undertaken at the University Hospital in Nijmegen, the Netherlands, where 505 visually handicapped patients were involved. Of those, it was found that sixty-three had experienced complex visual hallucinations in the four-week period before screening. Psychiatric examination of the patients revealed no other disorders which might cause such side effects. This and other studies suggest that as many as 15% of people with vision loss experience Charles Bonnet Syndrome hallucinations to some degree...

...Some Charles-Bonneters are able to banish their phantoms by changing the environment in some way-- such as turning the lights on or off-- though most of the time a patient is subject to their visions' whims. Others have resorted to befriending the apparitions, making idle one-sided conversation as the imaginary guests stare quietly. Fortunately the condition is almost always temporary, and in most cases the visiting visions fade away forever after twelve to eighteen months...

Click here to read the whole article.

Over the last 3 months my visions have shrunk in size and have become very infrequent. I attribute their fading away to the acupuncture and exercise regimen that I have followed.  Their disappearance, in addition to my improved capacity to read and scan, has made it possible for me to start driving again.  

Here are some additional resources for people with visual hallucinations. Click on the underlined letters to access the webpages.

Vision Aware: Why am I having visual hallucinations?

Lighthouse International: Charles Bonnet Syndrome

RNIB: Charles Bonnet Syndrome 

PsychCentral: Learning to live with Charles Bonnet syndrome

Eye-movement therapy with Eye-Search

 I started eye-movement therapy three weeks after the stroke.  I found Eye-Search during an online Google search.

Eye-Search is a free online eye-movement therapy for people with hemianopsia (loss of vision to one side) and spatial neglect (loss of attention to items on one side). It was developed by the Institute of Neurology of the University College London, UK. (Click here to access their website). 

The therapy involves playing a online game that has 16 levels of increasing difficulty. Each level involves 400 repetitions.  During each repetition, a ball rolls across the screen and jumps unexpectedly to the other side.  The player has to find it.  

This is a picture I took with my iPad of what the game looks like on the computer screen when you start. If you click here you will access a video on the Eye-Search website with a demonstration of the game. 

The purpose of the game is to exercise the parts of the brain that control eye-movements. Research has shown that lots of practice with an eye movement task improves visual search and visual exploration of the environment (1,2,3). Research has also shown that eye-movement training changes brain activation in the visual cortex (4,5).

When I started my eyes were slow tracking the ball. I had more trouble locating the ball when it went on the right side, my blind side, than on the left.  My eyes got easily tired moving left and right. But slowly, with repeated practice, the eye movements became faster and more efficient. I exercised every day, sometimes twice a day, and reached level 16 in two weeks.  Then I continued to play on level 16 trying to improve my reaction time.  When I started these exercises my reaction time was 2.2 seconds. With practice it got down to 1.2 seconds.  By now  I have completed 10,800 trials.  These days I play the game once or twice a week only.

What were the benefits from these exercises?  

• After the stroke my eyes felt slow and not well coordinated.  As I exercised them they became faster and better coordinated at tracking, focusing and scanning both during the exercises and afterwards in the "real world". 
• In the beginning I had trouble tracking the ball and at the same time finding where the cursor was on the screen.  Now it is all done in one fluid, easy eye movement. The ease of scanning has transferred to visits to the supermarket, scanning bookshelves, scanning plants to prune.
• Searching on the right side, the side of the blindness, was slower than searching on the left. The speed of detection on the right has improved, but still lags compared to the left. I think that with continued practice the two sides will become equal.
• Reading became easier, but I also used Read-Right, a free online reading therapy program that helps with reading difficulties .

Another interesting aspect of this therapy program is that at the completion of each set of 400 trials there are four tests to check one's progress. (Click here to access the tests). One of these tests is a visual field test. The Eye-Search therapy is not meant to improve the visual field. However, the visual field test at the end of every 400 trials gave me a chance to check how the acupuncture in combination with the exercises were improving my capacity to see and track my progress.  I included images of my results in my last post.

In a future post I will describe exercises I did in the "real world".


References

1. Rapid compensation of visual search strategy in patients with chronic visual field defects. (Click here to read abstract)

2. Comparing explorative saccade and flicker training in hemianopia: A randomized controlled study. (Click here for full text)
3. Current status of rehabilitation for patients with homonymous field defects. (Click here for full text) 
4. Eye-movement training-induced plasticity in patients with post-stroke hemianopia. (Click here to read abstract)
5. Eye-movement training-induced changes of visual field representation in patients with post-stroke hemianopia. (Click here to read abstract)