What is CVI?


CVI Meltdowns

What is a CVI Meltdown?

An incapacitating behavioural reaction to too many sights and sounds in children with CVI, has commonly been described by parents who have contacted us. We have called this a "CVI Meltdown", as this description is easily recognisable by parents and carers

To our knowledge CVI Meltdown, as we describe it, is not described elsewhere, and has yet to be the subject of academic study. Yet the behaviours that we as parents have seen and described to each other are so compelling, that we believe that we need to explain what we have seen, and how we have dealt with the consequences, despite the lack of previous published descriptions.

This section gives biographical descriptions of what families have described.

It is not known how many people with CVI are subject to CVI meltdowns.

This term is used specifically in relation to the very extreme behaviours seen when a person with CVI is unable to cope, and is mentally incapacitated by being overloaded with too many sights and sounds.

It should not be confused with other behaviours like tantrums, anger, stress or anxiety.

Connor's mother writes:

When describing CVI Meltdowns to various professionals, especially in the first three years when they occurred several times a week, with no obvious cause, I likened them to a child's reaction when they had their fingers slammed in a car door.

In addition to Connor's terror, as his mother I was worried sick, I thought something awful must be happening in his head, and no one had a clue. It was also socially embarrassing, this was not a child having a tantrum, or upset because they had grazed their knee, this was a child who sounded like he needed an ambulance called for him. I look back and see that a toxic combination of noise and clutter were two of the key triggers.
Connor's idea of hell on earth (and, by default, his mother's) would be the inside of a busy coffee shop.

What Causes a CVI Meltdown?

The key to a CVI Meltdown is that the individual is no longer in control of their actions. It is akin to the 'fight or flight' response, but unique to CVI because the person is unaware of why they are behaving or reacting the way they are, making the perceived threat even more frightening, and more challenging to manage.

Many things can cause a CVI Meltdown. The process might be understood as three phases:
1) the trigger
2) the emotional reaction
3) the behavioural outcome

Connor's mother describes one of the triggers of Connor's CVI Meltdown:

Connor loves television, so much that we have successfully used it as a conduit for all sorts of developmental things, especially learning to weight-bear, balance, stand, cruise and eventually walk (by placing a set of paediatric parallel bars leading to the television set). Obsessively, Connor would only watch programmes on one channel for babies. If a new programme was broadcast Connor would go into full blown fingers slammed in the car door, screaming floods of tears CVI Meltdown. One time they changed the voice of a regular character and it was the same response. Another time it happened on the television in his bedroom and he was scared to go back into his room for a week. We considered whether it was a change of noise, colour or movement, but nothing was obvious.

Connor's television, is his absolute safe space. Television is an enormous stimulant of course, although these programmes are designed for babies so the images are bright and bold, and movement is relatively slow, but considering what we know about Connor's visual world, it is still a big challenge. It is only because Connor feels so completely safe that he can indulge in the stimulation of television - I suppose a bit like loving rollercoasters, thrilling, but with the underlying knowledge that you are safe.
When someone messes with that feeling of safety, suddenly you feel very frightened.

An Imposter On the Scene

Mary has experience heightened levels of anxiety and anger over what seem like silly things, like someone moving something in her home.

Connor has a safe space where he completely let's his guard down, watching his television in his home. Mary also has a safe place, where she can completely relax and let her guard down, her home. These safe spaces are very important, but are also almost sacred to the person, and tampering with them is likely to result in a severe behavioural reaction.

An imposter, uninvited and unwelcome, had broken into their safe known worlds and the effect is overwhelming. This can lead to a sense of loss of control, rendering it all the more debilitating because they are not on their guard, and are not prepared for the 'shock'.

This experience, described by many parents, is discussed in more depth in the following section on Safe Places.

1) CVI Meltdown Triggers:

  • noise
  • visual clutter
  • busy environment / lots of movement
  • unfamiliar environment
  • unfamiliar people
  • revisiting somewhere previously experienced as stressful
  • an 'Imposter on the Scene'

2) CVI Meltdown Emotional Reactions:

  • totally overwhelming fear, causing a very real perceived threat of physical injury (for example from looming objects, due to optic ataxia)
  • emotional stress, which could be made worse from sensing the worry, stress, anxiety, frustration or anger of those caring for you
  • tiredness
  • brain fatigue (resulting from trying hard to cope against overwhelming odds)

3) CVI Meltdown Behavioural Outcomes:

  • headaches
  • screaming
  • lying on the floor / unable to stand / walk
  • physically attacking
  • escaping

Mary describes:

Before I knew that I had CVI, I experienced these meltdowns without ever knowing why, but just assumed that everyone had them every now and then for different reasons.

Mary's First ever CVI meltdown:

Mary still vividly remembers her first ever CVI meltdown, as it was so frightening because she had no idea what was happening to her. The meltdown occurred when Mary and her mum ventured out on their first trip to a shopping mall since the brain injury that caused Mary to develop CVI (although at this stage the CVI had not been diagnosed). Like most teenagers Mary loved shopping and was very excited about this little adventure. When they arrived at the shopping mall, Mary launched herself into her favourite shop, keen to explore everything that was on offer. However, Mary soon started to feel extremely anxious and panicked with no idea why. She felt herself go into 'fight or flight' mode and had to fight the urge to get away from the environment as quickly as possible, although she had no idea what was threatening her. As she started to feel more and more emotionally overwhelmed, she also started to feel that could not see or hear anything. At this point, Mary felt unable to move independently and needed her mum to help her get out of the shop.

Mary's Mum was very concerned about Mary and her deteriorating behaviour. She also noticed that Mary was extremely pale and shaky and was worried that something was seriously wrong. She took Mary to a cafe as she thought having something to eat and drink would make Mary feel better. However, it did not help at all, as by this stage, Mary was feeling physically sick and did not feel that she could eat or drink anything. Mary had also developed a thumping headache and all she wanted to do was get away from the shopping mall and back to the safety of her own bedroom.

Mary's mum was feeling very frustrated by the fact that she did not know what was going on and that she did not know what to do to help Mary. After this disastrous shopping trip, Mary felt scared to go to another shopping mall and wanted to avoid all challenging environments. However, Mary's mum thought that the best way to help Mary cope in busy environments, was to get her to spend more time in them. If Mary and her mum had known about and understood Mary's CVI, they would have been able to develop strategies to help make it easier for Mary to go to challenging environments like a shopping mall. However, Mary's CVI was not diagnosed for many years, so Mary suffered going through lots more CVI meltdowns as she continued to try and live like a normal teenager.

CVI Meltdowns and Headaches

Mary describes headaches, and how quickly, when there is too much visual information in a cluttered environment she develops headache:

"In terms of headaches, sometimes it's just the thought of being in a challenging environment that can bring on the headache. I guess it goes along with learnt behaviours - I know that the likelihood of getting a headache is high, so when I start getting stressed about being in a crowded environment it brings on the headaches."

Connor can't communicate to his mother that he is getting a headache. Connor's mother however detects the early signs of stress, and that something, not always obvious, is making him anxious, and without prompt action it will develop into a CVI Meltdown. The action is always to find a quiet place with minimal visual clutter and help calm and reassure him.

Effects of a CVI Meltdown

Mary has described how CVI Meltdowns cause headaches. Connor's mother describes multiple features that have been consistent after CVI meltdowns including:

  • less content / anxious
  • irregular bowel movements
  • sleep poorer than usual
  • clingy
  • reluctance to go out
  • reluctance to be with other people

It seems clear that these CVI Meltdowns have a tremendous physiological effect, and arguably should be avoided at all costs.

Mary learned to understand her CVI and developed strategies to manage her life, including avoiding CVI Meltdowns. However these are not always successful, as she describes here:

"My connecting flight home was cancelled due to fog and I had to transfer to a direct flight. This in itself was not a problem other than it upset me and made me anxious for a period of time, that I wasn't going to get home. So then when I was told I had to go back to the check in area, uplift my bag and re check in for the new flight, the panic really started. I had arrived at the airport with a colleague and hadn't taken any notice of where we had walked, so had no clue how to get back to the check in area. Because I was already in that stressed, emotional state, I felt unable to navigate my way around a busy, crowded airport to get to where I needed to go.

Of course I was unable to find the check in area or my bag and by this stage was feeling extremely upset, useless, vulnerable and frustrated. Realising of course that sitting down and crying was not going to help much, I tried to calm down and use my techniques to get me though. But I was in too much of a distressed state for these to be effective, proving again that once I have gone into fight or flight mode it is very difficult to come back from it. Fortunately a kind lady from the airline rang me to tell me my flight had changed and when I told her what I was trying to do and that I had a vision impairment and couldn't find my way around the airport (something I never do, as I never want to admit that I am incapable of doing something), she told me to stay where I was and she would come and find me to take me to where I needed to be - phew.

The experience left me highly emotional and very stressed - frustratingly so. A lot of the issue was related to my behaviour or phobia about difficult environments but some of it was still related to my vision. Even if I had managed to stay calm, I am not sure I would have been able to find where I needed to go."

CVI Meltdown Strategies

The key to avoiding a CVI Meltdown is understanding the reasons why they happen, which can only be achieved with a greater understanding of the person's unique visual world, for example:

  • fear of things suddenly appearing because they are not seen when moving, but appear when they stop
  • an inability to know where moving people are
  • too much to see, creating a visual overload
  • too much sound coming from lots of directions
  • new things appearing without notice in 'my safe space'

There are a few suggested strategies that can be tried:


  • nominate someone the person knows and feels safe with to reassure them
  • move the person away from any obvious sources of stress, including noise
  • move the person away from a visually busy or cluttered scene
  • be patient and give the person as much time as they need
  • have a calm 'chill out zone' available where possible


  • fuss, the environment needs to be calm and safe
  • crowd the person
  • talk over the person, keep all sensory input to an absolute minimum
  • don't let other people who think they know better tell you what to do - you know them best!

Lucy is a girl with CVI. Lucy has developed her own strategies to both identify and take appropriate action when faced with situations or environments she knows will be extremely challenging. Lucy's mother writes:

"Lucy copes well in lots of busy situations.

Here's my recent experience.

The family was invited to a christening recently.

Arriving fashionably late, we entered the venue to the reception.

Outside was a cold crisp quiet and bright afternoon.

The entrance foyer had a few steps to negotiate and then a main door.

We had a corridor leading to the function suite - a low-lit narrow 20 meters in length leading to a closed double door.

There were a few people in the corridor chatting.

When we opened the door to the function suite - it was in full disco mode.

We proceeded across the darkened, empty dance floor in a family group.

People approaching shouting hello at us over the booming music.

Lucy pulled on my hand and dragged me straight across and out the other side.

At the far end was an open door to a brightly lit room, where it was quiet.

We did not even take our coats off - we simply made our excuses and left by the same way.

Overload - meltdown - call it what you will.

Lucy was totally fine afterwards - she knew how to get herself out of the situation and sought refuge somewhere quiet.

Katherine is another girl with CVI, who like Lucy (above) has learnt to anticipate situations that she will find challenging, and will act to avoid them.

Katherine's mother writes:

"I'd describe Katherine as similar to a wind-up toy during a shopping trip. Her behaviour changes and it appears like she's desperately trying to gain control of a situation that she has no control over, if that makes sense. I only take her when I have to these days, as she finds it very unpleasant, plus, I never get to complete what I've set out to do, as they are always cut short, because she constantly asks to leave or becomes quite irritated. I'd also say her vision becomes worse, like a temporary blindness, which could be why she likes to take refuge behind the shopping trolley! I also find this when she is introduced to new surroundings, I always feel a slightly stronger grip to my arm or hand.

Do you think how they feel is similar to us being at a busy airport or train station when you're running late and you haven't got a clue where you need to go? Anxiety levels soar, your brain shuts down and you end up just running around in circles? I've been in that situation before and it's amazing how quickly you lose the ability to make sense of what's around you, even down to reading information or a map. We can make sense of such events but it must be terrifying for our children who can't.

Mary, Lucy, Katherine and Connor all demonstrate how challenging some environments can be, but their behaviours and reactions are quite different. This is where the CVI Classifications are useful:

  • Connor, CVI Classification 1 does not understand what is happening, he is unable to rationalise what is around him and his reactions is demonstrates this, it is very primitive, he goes straight into CVI Meltdown. Connor's actions are driven by self preservation.
  • Lucy and Katherine are likely to be CVI Classification 2, and can anticipate, rationalise, plan and act to a degree. Their actions are also mostly driven by self preservation, but there is a level of control and social awareness that stops them having a CVI Meltdown, and they both adopt strategies to move away from the threat as fast as they can. Had Lucy or Katherine felt more threatened or less in control, they may well have had a complete CVI Meltdown rather than avoidance behaviours. Others in this group (CVI Classification 2) may be more like Mary in their behavioural and emotional responses:
  • Mary (CVI Classification 3) has developed a great understanding of what 'normal behaviour' is meant to be, and tries very hard to conform with this. Mary tries very hard to fight instinctive emotional responses.


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