Ever been baffled by what an Usher person sees? Or wondered what it would be like to climb inside their eyes through a John Malkovich style portal to see just what they can see? People with Usher are born or become deaf but then develop Retinitis Pigmentosa usually as teenagers or adults – an eye condition which can baffle even those who have it. Most are registered blind by around 40 years old. Yet most people with Usher do not feel blind, they can still see plenty. I am registered blind but my world is not devoid of sight, far from it. In many ways the way I see the world looks just the same as before. It looks normal. It is not a scary or dark place. It shouldn’t be feared. I just see differently. My vision just doesn’t do all the things it should.
Bear with me while I do my best to explain by taking a little detour into the visual world of birds of prey. Random but relevant.
Kestrels flying so high that they look like a speck in the sky can see a tiny 2mm insect scuttling by your feet. Their colour vision is so sharp that they can see trails of mole urine highlighted in the grass.
The price the kestrel pays for such daytime prowess? Its vision is so poor in low light that it must go home to roost at night.
The huge blinking eyes of an owl allow it to see one hundred times better than us at night. Owls can scan a field in the dark and spot the wriggle of a mouse in the gloom. Impressive, right? The disadvantage is an owl can’t see colour as well as humans can. Their daytime vision is a bit rubbish and much less sharp than ours.
Why am I banging on about this? Well, human eyes are just as remarkable. They may lack the same wow factor but have none of the drawbacks. Human eyes are nifty mix – a little bit of kestrel, a little bit of owl. Humans can see well in the day and in dim light.
Imagine a retina – the middle of your eye is the kestrel bit. It is full of cells which give the sharp colour vision that you use for seeing details. These ‘kestrel cells’, otherwise known as cones, help you read, thread a needle and see people’s faces. They deal with the detail.
The owl bit of the retina is round the edge – where there are lots of cells called rods. Try paying attention to your peripheral vision. You can’t really see much in the way of colour or detail, can you? Things look pretty vague out to the side don’t they? But this vision is still essential.
Even in the day the rod cells tell you where obstacles are. They make you sense things moving quickly towards you and allow you to react even before you know what they are. If you are deaf they alert you to a hand waving for your attention or people in the room.
Rod cells let you swat a fly, catch a ball and let you know where the kerb is as you walk along daydreaming. You don’t have to move your eyes around as you walk because the owl bit round the edge of your retina is constantly scanning the environment for you, even when you are not thinking about it. It will tell you where the kerb is even when you are not looking directly at it.
When you are searching for your keys or sweeping crumbs off the dining table, you use this owl vision to scan before homing in on your target with your sharper kestrel central vision.
You rely on the owl bit of your eyes even more at night. It is this vision that alerts you to the silhouette of tents in a field or the outline of furniture in your bedroom. It let’s you see your sweetheart in candlelight or understand the signs of a deaf friend in the backseat of a dark car. It finds the light switch in the dark.
Every day you use both your kestrel and owl vision, switching between them effortlessly. When you cross the threshold of a pub for Sunday lunch on a sunny day, for a moment it looks really dark inside before your eyes adjust that’s your kestrel taking a break and your owl stepping up to the plate. They are a team – taking in turns to lead and to take a break, depending on the lighting conditions or the task at hand.
So what has all this got to do with Usher? Well for a person with Usher the owl bit of their eyes is refusing to cooperate. It’s got lazy or popped off it’s perch altogether. The owl cells round the edge of their eyes are slowly dying. Their peripheral vision is shrinking.
But the world still looks the same to the person with Usher because the kestrel is still wide awake and doing it’s bit. Usher people often still have sharp, clear central vision. It is the corner of their eye that is missing. This is why the Usher person often does not feel or look blind. In the early days they may not even be aware of their vision problems. They just move their eyes around more to compensate.
In good light the Usher person can see straight ahead but they don’t have owl vision automatically alerting them to sudden movement, like people waving or walking in front of them. But they can still see. It is bizarre. It can be baffling for them and those around them working out why they can see many things perfectly but totally miss others.
Back when I had some peripheral vision, a person in the corner of my eye would wave for my attention and I wouldn’t notice it, and then I would realise that I could actually sense the person stood there but I didn’t register their movements, there simply was no waving hand. The kestrel bit of my eye was working but the owl bit let me down.
The kestrel has to work flat out using only central vision to compensate for the lazy owl. The Usher person has to scan their eyes from side to side and up and down as they walk. Look ahead is there any dog poo or a kerb? Look up any branches? Look left and right for people cutting in front of you. They seem to appear from nowhere as if conjured from thin air. I have to remember what is up ahead, because the nearer it is, the harder it is to see exactly where things are. It is exhausting.
It’s a bit of a myth that Usher vision is like looking down a long tunnel. It isn’t. At least it isn’t for me, yet. It is more like a funnel. My vision starts narrow and opens out. I can see things in the distance just as well as you can, the world looks just the same as it always did, but if you are standing right next to me I can only see your mouth moving. No eyes, no hands just your mouth. I have to move my eyes around your face to take it all in and piece together your expression and the ‘mood’ of what you are saying. Just take one step back and I can see your whole face. Another three steps and I can see your hands as well. Ten steps and I might even be able to see your feet.
While playing badminton, I can see a perfect shuttlecock hurtling towards me through the air but around 6 ft away it just disappears, and more often than not ends up on the floor! I can see a whole crowd of people ahead but when I am among them, I can’t keep track of who is where and end up clumsily bumping into folk. I’m only blind to things when they are very near.
This is why I can see things at the back of the fridge perfectly but completely miss those at the front. That is why Usher people knock over drinks placed within arms reach. They just don’t see the bit of the table nearest them.
Without owl vision, I am useless at finding things dropped on the floor. I can only scan with the middle part of my vision and it takes an age. It can be quicker to use my feet to search, or to get down to floor level and scan the horizon of the floor for something sticking up.
My good kestrel vision alone doesn’t help me see bikes zoom past, or notice steps, or avoid banging my head on cupboard doors. It doesn’t help me to find the dratted cursor blinking on my computer screen, or to check the table for crumbs. I have to step back and then I will notice the bit of dirt I have missed. It’s pretty irritating.
There is no owl to take over when I enter a dim pub so my eyes are incredibly slow to adjust, in fact they don’t really adjust properly at all and I often end up playing skittles with the bar stools.
At night things get tougher. I am dependent on a tiny circle of useless kestrel vision which was never designed for seeing in the dark. By scanning, I can see by piecing things together. This is just about good enough to navigate through a familiar well lit street if no one is around. In fact to my brain the street scene looks pretty darned normal. The kestrel sees enough to put the scene together. I do not feel blind. But as soon as people are milling around, pets, children, cars, bikes or those blasted trolley suitcases then I am scanning frantically to avoid collision and embarrassment. My brain can’t fill in the missing pieces fast enough and I become disoriented. That’s when it hits home how little I can really see – even though I still feel like I can see – which to be honest baffles even me.
Of course no two people with Usher or RP are the same. We all have different vision loss and are at different stages. Some will have very different vision to me, but I hope that this post reveals some of the mysteries of our vision and makes people understand that what we see is not frightening or desolate. It’s just a bit like doing a jigsaw with your eyes.