CVI – Cortical/Cerebral Visual Impairment 

I’m writing this blog after talking to a friend of mine who possibly has this condition, one which I also have but is undiagnosed as a lot of professionals don’t recognise CVI as a VI because the eyes themselves appear normal and it is in fact the brain with this condition That is affected because the eyes will see things but the brain can’t process what the eyes are seeing so the images get lost or stuck somewhere in between eyes and brain. Normally like myself this condition occurs at or shortly after birth due to brain damage or some sort of brain trauma so this type is called Congenital CVI but what I didn’t know same with Cerebral Palsy thanks to the Paralympics that these 2 conditions can also be acquired later in life. It does seem that the focus is mainly on children with CVI and not much on adults which is kind of odd because either we’ve had it since we were children and it won’t go away or if can be acquired and I think it’s those along with children need help and support for this condition but hopefully as more research is being done more professionals will know about this condition and acknowledge it as a VI. 

People often ask as they do with any VI person “what can you see?”. Now it’s not black and white unfortunately as everyone sees differently and because I’ve never seen normally it can be quite hard to explain, thankfully I found some fairly realistic simulation specs online which have helped people to understand a little and it’s quite interesting what different people see with these specs. Most people who have their 2 eyes working together when they put the glasses on they will see double but thankfully most of the time unless I’m tired or ill or trying to focus too hard because my eyes work completely separately to each other I don’t necessarily get the double vision. So I will try and explain as best I can what I can see to hopefully give people a better understanding:

The world around me is like a jigsaw puzzle so when I first go somewhere new my brain needs to process what my eyes are seeing and that can be very hard, tiring and takes a lot of concentration as it tries to figure out what things are and so in my home town or workplace which are familiar areas my brain can fit missing pieces of the puzzle even though I may not see it, obviously there are constantly changes which again throws the brain into confusion like bright lighting including the sun or in the evening which makes everybody and everything look like silhouettes, at night or in darkness I see nothing unless some light is coming through. have no peripharal so it’s mostly in the centre what I see and my eyes don’t work together so one may see something whilst the other will see something completely different, sometimes I see double or one and a half of something. It’s worse if I am tired or ill. I have nystagmus as well and a block squint, one eye is normally worse than the other and in my case it’s my left so I see most out of my right. I can’t see what’s on the floor so only what’s at eye level and when I try and pick things up or reach for something or touch something I sometimes miss it. The brain works in mysterious ways and I cope relatively well as my brain has adapted to my way of seeing it just doesn’t transfer the images the way it should. I have no 3D vision so people look like cardboard cut outs, steps, stairs, kerbs etc are all flat so they are difficult to judge and traffic is hard to judge the speed so I’ve had near misses but thanks to my guide dogs I’ve been saved every time 🙂 facial expressions I can’t distinguish so I go mostly by people’s voices or footsteps. Crowded and unfamiliar places are a nightmare and a challenging undertaking which can make me stressed because there’s too much for my brain to take in so it gets overloaded which in turn gives me headaches because it takes an awful lot of concentration. Sometimes sitting in darkness is actually lovely because I don’t then need to focus on anything or if I’m on my iPad then that’s the only thing I need to focus on because everything else around me is black so my eyes even though they still need to process and read it’s a lot less strain than having to try and process everything Around me when the light is on or I’m outside. Reading isn’t an easy thing because of my nystagmus everything swims on the page and it would take me far too long to read a book because I can’t read more than a few lines before feeling the strain so I listen to audio books now and if I do read I try and have the font size to 36 for instance as that’s comfortable reading but If it’s too big or too small there’s then too much movement for eyes to cope with for instance if the letters are too large I only see a portion of it and it takes much longer to figure out what that letter might be and that’s why magnifiers are not the best for me even though I have found an electronic one that is really helpful. 

High contrast things are best because otherwise things merge into each other and I can’t figure out what it is for instance kerbs, roads and pavements all look the same and are all flat to me so I can’t distinguish what is what because it’s all grey but again when I’m used to an area whether it be pitch black or daylight My brain will remember when there is a kerb etc but even when I’ve been to a familiar place a 100 times one time I will notice one thing and yet I’ve passed it so many times before or I won’t notice something or my brain will think there is something in my path when there isn’t anything. Most of the time we look as if are just fine but it takes a lot of hard work to process the world around us and that creates the eye strain, tiredness etc which the public don’t see and CVI does go hand in hand with other disabilities so it’s not just the eyesight it’s the whole package. 

I’ve attached a video link from YouTube which explains better than I do about CVI. Eyes are not the only thing that help us see the Brain is a major part and if the nerves don’t connect it is kind of as if the images are bouncing back and forth but going nowhere. 

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