There are many conditions that lead to Charles Bonnet Syndrome (CBS), with macular degeneration remaining one of the leading risks for this fascinating condition.1
Although everyone with CBS is likely to experience a different path, Chris Hansen suspects there will be many similarities.
In this brief account, he has detailed his own encounters and described the practical and logical ways he has learned to live, and become more confident with CBS by proactively managing his visualisations.
In doing so, Mr Hansen hopes eye care professionals will be better equipped to understand and help patients with CBS to find comfort in their visualisations.
Charles Bonnet Syndrome (CBS) involves the experience of vivid visual phenomena following vision loss that likely originates directly in the brain rather than the optic nerve or retina. Similar to phantom limb pain experienced by new amputees, it causes mentally healthy people to experience visualisations that they know are not real.
As my condition worsened, the visualisations became increasingly scary, most likely due to the stress being placed on my heart and lungs
When I developed CBS in early-2019, I was surprised to discover that very little information was publically available, and there were next to no first-person narratives. Most of what I could find was third party and treated the condition as an illness or disease, with a focus on medicalisation. In fact, one article described CBS as ‘hallucinations’ with ‘no known cure’; and said symptoms may be reduced by using psychotic drugs.
As someone who is totally blind, I refer to CBS as ‘visualisations’, rather than ‘hallucinations’ and I do not believe that this is an illness that needs to treated. In fact it is quite the opposite – CBS provides a comforting image of my surroundings and in most cases, is preferable to total blackness.
CBS: The How and Why
The prevalence of CBS varies according to study, ranging from 0.4% to 30% of all vision impaired people. However, the numbers experiencing CBS may be higher than reported with many patients not disclosing their symptoms due to fear of being diagnosed with a mental illness.
In a visually-healthy person, images are transferred, via the optic nerve, to the visual cortex where they are assembled in the accessory brain areas along with information from other senses such as sound, touch and smell. There, they are formed into a memory that is stored away for future retrieval. When memories are retrieved for interrogation, they do not have exactly the same clarity as a visual image – some details are precise while others are vague.
In the case of a person who is totally blind, there are no images or signals travelling along the optic nerve. Instead the brain uses the other senses to pull an image from memory to fit the current circumstances, then generates a visualisation known as CBS. This visualisation is created on the fly, and, like a movie, it may suddenly change to a completely different image if triggered by an external sense.
If the senses detect a new situation, such as when talking to an unfamiliar person, the brain draws on similar memories in an attempt to generate its own image.
Memories formed from CBS visualisations are stored, and can be retrieved later, with the same amount of detail as pre-blindness memories.
PROLOGUE: DAY ZERO
On 30 March 2019, I became totally blind during a coronary bypass operation at Strathfield Private Hospital in Sydney, New South Wales. During the operation I went into anaphylactic shock due to an allergy to one of the medications administered. To enable the procedure, my heart had been stopped by cardioplegia, so when my blood pressure plummeted to single digit figures, the surgeon was not in a position to withdraw from the operation. In an attempt to sustain life, the anaesthetist performed life-saving management practices and a total of 12 litres of additional fluids were pumped into my body. It was not until three days later, when I was awoken from a post-operative coma, that I discovered I had total bilateral blindness.
An urgent, high resolution MRI taken at Royal Prince Alfred Hospital, showed no reason for my blindness. The medical staff, surgeon, anaesthetist and others were completely surprised that I had lost sight in both eyes yet had not sustained any damage to organs such as my kidneys, liver or brain. All they could determine was that my optic nerve had suffered damage due to prolonged low oxygen levels and blood supply, at some point during the operation.
The Shock Phase
When I woke I was in shock. My ears were ringing and all I could see was a psychedelic brightly-coloured, moving pattern. It was as if my brain was throwing up a test card saying, “I don’t know what is going on but here is something to look at in the meantime”.
This visualisation didn’t change for 24 hours. Psychedelic, teardrop shaped amoeba-like figures moved and squirmed, filling my ‘visual screen’ with no white space between them. Every now and then one would pop forward then recede.
While fascinating, I had no relief, and at one point woke every hour throughout the night to find the blobs still squirming in my vision.
My wakefulness was, in fact, caused by pericardial effusion – the lining around my heart was filling with fluid to the point where it could no longer pump very well, which in turn caused my lungs to fill with fluid – I was struggling to breathe.
As my condition worsened, the visualisations became increasingly scary, most likely due to the stress being placed on my heart and lungs.
Further surgery removed the fluid build-up and with that, the scary images as well.
Over the days that followed, my brain went through several phases with visualisations that went from absurd psychedelic patterns, to orderly, marching figures, through to ridiculous cartoons.
Finally, my visualisations matured into more comforting images that seemed to be triggered by people talking or events around me. They were calmer, more realistic and included realistic images of friends and family drawn from memories, which I cherished.
The images I did not want to see disappeared as I began to purposely and mindfully reject them, and I learnt to control when and how more positive images appeared by managing my environment. On the few occasions when the scary images return, for example, I yell and wave my hand across my face until they disappear completely.
THE UNUSUAL TRAITS OF CBS
When a sighted person looks at the world around them, their view is very similar to looking through a pair of binoculars. In other words, there is a black border around the extreme left, right, top and bottom. When a person looks down to the right or left their nose is always visible as an outof- focus area, much like a mountain peak between their eyes.
My CBS visualisations – regardless of whether they are moving or static – also have a border. And, even more enigmatically, I see an imaginary nose poking up between my two eyes. If I bring my finger up to touch my nose, I can immediately see it, although it is out-of-focus. If I move my finger away from my nose, my finger seems to magically disappear although the background picture of the visualisation remains.
Given that my optic nerves no longer receive any signals, this detail is quite astounding and something that I continue to ponder. Is the brain simply being really precise and producing this border around the visualisation to make it seem genuine?
It opens up the possibility that all images stored by the brain as memories include the border of binocular vision around them, but I find this a bit of a ridiculous idea.
Another slightly puzzling CBS phenomenon is my inability to zero in and focus on any particular part of a visualisation without it immediately becoming less distinct and beginning to change. If I move my eyes to try and focus on the detail, the whole image is moved left or right, which is unlike and different to actual vision.
Heightened ‘Other’ Senses
One day while in hospital I picked up my phone and the USB cable fell out, touched my leg and landed on the floor. ‘Seeing’ the cable coiled in a loop, I reached straight down and grabbed it by the neck then plugged it back into the phone before realising what I had done. I had very accurately visualised the cable sitting on the floor, and where the end of the cable was located.
When I am travelling in a car, I experience visualisations of ordinary looking houses that curiously move along at about the speed the car is moving.
If the car slows to stop at the lights, the images around me slow or stop and, as we pick up speed, the houses move past faster and faster.
Once, when trying on a pair of sunglasses, I stood in the shop and looked out at the street. My visualisation showed me the street. When I put the sunglasses on, the visualisation immediately became darker – exactly as it would if I were sighted. I was so surprised that I lifted the sunglasses up and down several times, and sure enough the visualisation switched between dark and light.
Visualisations of objects that I know very accurately from my ‘sighted’ experience are perceived with their exact dimensions. For example, when I place my hands on the dining table, or I sit down for a meal, I can immediately visualise the full size of the table with all the chairs around it. I can see and visualise my plate of food in front of me and a glass of drink to my left.
I’ve had a few strange things happen when ‘looking’ at mirrors. Once I was standing in front of the mirror in my new bathroom, which was built while I was in hospital. I immediately thought, “What an idiot, you don’t need to stand in front of the mirror, you can’t see anything”. It was at this point that I suddenly realised that while I could visualise the new mirror, I couldn’t visualise myself in it. No matter what I did, I couldn’t find a reflection of myself in that mirror.
I thought about this for a while, then decided that, because I was not familiar with what the mirror looked like, it was impossible to visualise a reflection in it.
To test my theory, I went to the bedroom mirror that has been above my dresser for over 20 years. It’s always been too short for me, so I have to bend down in order to see my face. Sure enough, there I was standing in front of the mirror – my head cut off as it always was, at this particular height.
Near and Far
Most of my visualisations appear to be with realistic distances. For example, if I’m outdoors, visualisations of trees in the distance appear to be in a normal perspective. However, I’ve noticed that when I’m very tired or mentally drained, the visualisation is right up close and in-my-face. It is very disorientating and I find it quite troubling. It immediately tells me I need to rest in order to normalise the visualisations.
Sometimes I wake during the middle of the night with a very bright, close-up wallpaper-like visualisation that causes me to look around in search of the light source. When I study the visualisation over time, I can tell that the light source is behind my head and up to the left. Quite often I can see shadows on objects that are in the visualisation and this confirms the location of the light source.
When I’m tired or relaxed, I experience an unusual visualisation that consists of a whole series of pictures. It’s almost like a deck of cards, each one with a different image – people, animals, or cartoon-like characters – being held up in front of me, rotated, moved closer, then shuffled into place until my entire visualisation is full of different images.
MANAGEMENT TECHNIQUES: MOVING FORWARD WITH CBS
It has taken several months to get used to living with CBS, and over that time one of the most important things I’ve realised is that I can control my visualisations by using my imagination and controlling my environment.
Firstly, it’s important to control the environment in which the visualisation occurs. Music seems to have made a big difference for me – for example, quiet music allows me to experience calm images for longer periods of time, rest well, wake up feeling refreshed and then, once the music is resumed, so too are the visualisations. Once your patient finds a particular type of music or artist that produces their preferred visualisations, they are likely to be able to trigger these visualisations when they want them, rather than sitting in darkness.
Another environmental factor that influences my visualisations is temperature. When I am indoors, I normally will get an indoor visualisation of the room. However, if the temperature is cool (18 ° or lower) then the visualisation often changes to an outdoor scene. Cool weather evokes images of more shady trees than does warmer weather, and once, when I was told it was snowing outside, I could immediately visualise everything covered in white, despite not being able to see falling snow. The visualisation followed my belief or perception that it was snowing.
Sinister or unfamiliar visualisations can be disturbing and if I try to drill down on them or examine them, they can become more significant and linger for longer. Whenever I experience a disturbing visualisation, I immediately take action to dismiss it by leaving the room and turning my attention to another activity.
Often things that people are talking about in a conversation can suddenly trigger a new visualisation. While I find this quite interesting, sometimes the new visualisation will replace the one I was already enjoying. I’ve found that by getting up, briefly moving to another room, then returning, I can re-live or restart the old visualisation I preferred.
If I become physically or mentally tired, my visualisations become very strong and uncontrollable. Visualisations that usually have a 3D panoramic effect become 2D and very close to my face. Rest is always the best solution.
I started out being scared and not very comfortable with CBS. Now, I feel the opposite.
Learning to control CBS is very important because it can allow your patients to live a more normal life without stumbling about in the darkness.
However, it’s equally important to remind them that a visualisation is purely that, just a visualisation – the exact spatial proportion and location of a visualised object is not always as it is in the real world. They should also be particularly careful of steps because I have found that visualisations don’t seem to include them.
Chris Hansen is an Information Technology consultant and a member of the well-known Hansen optometry family from Orange in New South Wales. In March 2019 he experienced an anaphylactic shock while undergoing heart surgery, which left him blind and with Charles Bonnet Syndrome.