Tag Archives: Visual Field

Visual fields

Living with peripheral vision loss can be a tad embarrassing at times.  It’s caused me to let out a loud girly squeal whilst using the photocopier at work, when the Dean (no less) suddenly appeared on my bad side, seemingly out of nowhere, and boomed “Good morning!” at me.  It’s resulted in me leaping a foot in the air and bashing my knuckles on the hand-dryer in the loo at work, when a student materialised out of thin air at the hand-dryer alongside me.  It’s caused me to berate my good friend when she spotted me in the distance one day and ran to catch up with me, grabbing my right arm as she did so and thereby scaring the living daylights out of me.  I frequently jump violently and then swear with equal violence under my breath when a cyclist whizzes past me as I walk along the paths on campus.  After stumbling over students’ bags in the entrance to my workplace on several occasions, I now walk round and use a different door if I need to enter or exit at the time a lecture is due to start or finish.  Last but not least, I’ve acquired some interesting bruises on my right shoulder due to various minor mishaps.

The loss of peripheral vision in my right eye is due to the 360 degree laser surgery which was done in an attempt to stop the retina from re-detaching and to try and save my central vision.  I suspect the three retinectomies (where part of the retina which won’t lie flat is physically cut away) probably haven’t helped matters, either.  Of course, unless people have actually experienced loss of peripheral vision themselves, it’s difficult to expect them to fully understand.  I thought perhaps a visual interpretation might help, and therefore sought the assistance of my personal patient photographer, who happily doubled up as a person with properly working peepers.  (It’s such a shame that the ‘h’ in ‘photographer’ messes up the alliteration there; however, I digress…)  Our highly scientific peripheral vision experiments when looking at the fields just down the road from my house, followed by extensive jiggery pokery with photo-editing software, led to the following results…

The picture below shows the complete field of vision of a person with properly working peepers, with both eyes open:

Fields

The visual field of someone with ‘normal’ vision.

The following picture shows the field of vision of both a person with properly working peepers and myself, when our right eyes are closed (so looking only through the left eye):

fov-res-w

Visual field of left eye.

The next picture shows the field of vision of a person with properly working peepers, whose left eye is closed (so looking through the right eye only):

fov-les-w-a

Visual field of right eye of someone with ‘normal’ vision.

The final picture (below) shows the field of vision in my right eye, with my left eye closed:

fov-les-w-e

Visual field of my right (RD) eye.

If you compare the last two pictures, you can get some idea of how much peripheral vision I’ve lost in my right eye.  If you look at these pictures in conjunction with the images in my earlier blog post, Do you see what I see?, this gives the most accurate representation possible of my waffy vision as it is at the current time.  So with that in mind, if you could kindly avoid sneaking up on me on my right-hand side, that’d be just grand…

Note: Grateful thanks to the patient photographer for producing these images for me and putting up with extensive peripheral vision analysis in the process.

 

 

 

 

Blind spot

After having my last check-up appointment at Moorfields cancelled at pretty much the last minute (https://rdramblings.wordpress.com/2016/04/03/q-whats-more-stressful-than-an-impending-eye-appointment/), I was more of a nervous wreck than usual by the time the hours, days, and finally three weeks had slowly dragged by until I eventually reached the rescheduled date.  After getting a few headaches I’d convinced myself that my pressure must be high, I was already terrified of the inevitable discussion of when surgery to remove the oil should take place, and to top things off I’d noticed a blind spot in my good eye (perhaps I should describe it as ‘better’ eye rather than ‘good’ eye) which had been freaking me out for a good few weeks.

I only noticed this during the course of my usual visual field checks at home.  One day I realised that when I sat at my table and stared ahead with my bad eye shut, I was unable to see one of the pictures on the wall across the other side of the room with my good eye.  Once I’d calmed down slightly from my initial panic of thinking, “****, I need to get to Moorfields first thing tomorrow morning”, I remembered that various people on the RD Facebook support group site had discussed suddenly noticing blind spots and it had turned out to be a result of laser surgery and they just hadn’t noticed them before.  So I told myself it could just be from the cryotherapy I’d had in that eye to mend the two tears back in April 2014.  Or, I told myself, it might be the natural blind spot which everyone has.  Or, I told myself, it might be a hole or a tear in the retina.  After telling myself all this and freaking out all over again as a result of the last possibility, I’d then try to calm my breathing down and stare at the blind spot once more, willing it to be a figment of my imagination.  It wasn’t.  I obsessively measured it each day (I’m not admitting to how many times a day) by using various visual markers so that I would be able to tell immediately if it got any worse.  I also started ‘looking’ for it when I was out and about.  This was not really a sensible thing to do.  Once, during a walk down the road, I managed to make an entire red telephone box disappear into the blind spot, which caused me to feel rather sick.  However, as the blind spot didn’t seem to be growing when measured against my set markers at home, and I wasn’t getting any other new symptoms, I gritted my teeth and attempted to plough on through my daily life as normal whilst desperately trying to quell the evil little voice inside my head that said “It’s going to be a tear, it could detach at any minute… you’ll end up at that appointment and they’ll whisk you straight into surgery”. 

We arrived at Moorfields in plenty of time – so much so that we even managed to nip into the cafe to get a cuppa to take down with us for the long wait in the clinic.  “What are you doing?”, asked my sister in aghast tones when I sat down with my cup of tea.  “I don’t want to go down to the clinic!”, I said, clutching my stomach which had been churning uncomfortably for most of the morning.  However, down we went, reluctantly.  We settled down for the long wait, briefly pausing in our important discussions of setting the world to rights to glare disapprovingly at one patient who obviously wasn’t accustomed to the NHS in general and eye clinics in particular as he proceeded to harangue the receptionist and demand to know when he would be seen.  We observed with disgust as he turned his back on her whilst she was still explaining that she would check where he was in the queue, and plonked himself back down inserting headphones into his ears as he did so.  Unfortunately, I’d already disposed of my banana skin, otherwise I’d have been sorely tempted to toss it under his heel and watch him go flying down the shiny corridor floor.

We didn’t have to wait too much longer before I was called in by one of my consultant’s team.  Upon asking if I’d experienced any problems since my last check-up, I told him about the blind spot and he said that he ‘hoped’ it was my natural blind spot, which everyone has.  Following the usual drill with each eye in turn (see https://rdramblings.wordpress.com/2015/07/30/a-grand-day-out-at-moorfields-eye-hospital/ if you’re interested to know what this is), he sat back and used magical words such as ‘okay’ and ‘stable’, as well as assuring me that the blind spot was indeed simply the natural one.  I quickly suppressed my urge to leap up and do a little dance as he then started talking about the dreaded subject of surgery to remove the oil.  However, even this ended happily as in answer to questions, he said there was no clinical need to remove it immediately and it would be fine to wait for another few months.  Of course, I’d still like a miracle, but while I’m waiting for this to be arranged, I’m more than happy with the outcome of today’s appointment.

In the meantime, if anyone’s wondering, let me just explain the sciencey bit about the blind spot, which all of us have.  Light enters our eye through the pupil and hits the retina at the back.  The optic nerve then carries this information to the brain.  However, the optic nerve is kind of ‘plugged in’ to the retina itself, which means that this part of the retina is in effect redundant, thus creating a blind spot.  Most of the time, the other eye will see what’s in the blind spot, but if the person is only looking through one eye, the brain just fills in the spot by taking information from the surrounding area.  So, for example if a picture on a green wall falls into the blind spot, the brain will fill in the blind spot with the green colour of the wall and it will look as if the picture has just disappeared.  This is what was happening in my case at home, doing my visual field checks.

To demonstrate this, have a look at the picture below.  Close your right eye and look at the cross on the right.  You should still be able to see the dot on the left, but don’t focus on it.  Keep your eye on the cross and move your face slightly closer to the screen, and then further away again.  At some point, the dot should disappear.  At this stage, you have found your blind spot. Do the same with your left eye, but this time focus on the dot and move around until you see the cross disappear.  The same should happen if you use a different coloured background, but your brain will fill in the colour of the background.

blind-spot

 

RD Tics

Since dealing with retinal detachment, I appear to have picked up a number of behavioural quirks and odd habits.  I’m able to laugh at some of them at times, but at other times I feel as if I’m going everso slightly mad.  Here are just a few of them, together with explanations in the hopes that people will understand that there is a reason behind my sometimes strange behaviour…

  • The checking visual field tic
    This is when I sit in a certain place and shut one eye then look up, down, left and right with the other eye, to ensure that I haven’t lost any more peripheral vision before proceeding to do the same thing with the other eye.  My office buddy at work has now got used to this, and simply asks in a matter-of-fact manner whenever she catches me doing it, ‘Is everything okay?’
  • The “Oh my God, I’ve just seen a new floater” tic
    This takes the form of jumping in extreme alarm at any black object which happens to suddenly catch my eye.  It can be anything from a fly, a spider, a swooping blackbird, or, as happened recently, my black umbrella cover floating gently to the floor.  The jump, gasp, and sometimes shriek is generally followed by a couple of seconds of intense staring as i realise that the said fly / spider / blackbird / umbrella cover REALLY isn’t a new floater after all, and gradually my heart rate returns to normal.
  • The staring in the mirror tic
    Probably mistaken for deluded vanity when in public toilets, this is actually a compulsion to check my eye for redness, swelling, gunk, possible signs that the oil may have leaked through to the front of my eye, or just generally checking how dilated the pupil of my surgery eye is that day.
  • The sudden staring off into the distance mid-conversation tic
    I’m told that this can be quite off-putting.  Well, trust me, it’s even more off-putting for me as I do this when I think I’ve ‘seen’ something which causes my heart to pound and teeth to clench in fear.  Whatever it is that I think I’ve seen, it usually causes me to stand and stare in terrified concentration for a few minutes until I’m able to figure out a logical explanation for it.
  • The “Does my eye look alright?” tic
    This usually occurs in places where there’s no access to a mirror, and simply demonstrates the need for reassurance that yes, my eye does look relatively normal and there’s nothing immediate to worry about from the outside of it, at least.

So, for anyone reading this who is fortunate enough to have healthy peepers, please bear with us RD people and try to understand that, much as we would love to, we can’t escape from our waffy vision.  I’m afraid I don’t know what the answer is in dealing with it all, but if anyone has any useful suggestions then please let me know…

Panic and paranoia

It’s been a bad couple of weeks on the eye paranoia front.  On a scale of one to ten (one = I don’t even think about my eye issues, and ten = ringing Moorfields and looking up train times whilst trying to breathe evenly in order to calm my pounding heart), I’ve probably been about a seven or eight this week.  The fact that it was my first week back at work doing full-time hours probably hasn’t helped matters.  Even on a good day, my eye aches and feels uncomfortable.  After a full day at work on a computer (even with breaks and leaving on time), I’ve been coming home with my eyes feeling scratchy and sore, and so tired that I just want to close them and sleep.  Just to add another dig in the ribs, my companion Insomnia has been rearing her ugly head again, too.  I can’t bring myself to do what a friend was once advised for his insomnia – go downstairs and read the ‘phone book until he felt tired and then go back to bed and try and sleep.  So instead I just shift from one side to the other (still not allowed to sleep on my back), and try to think of happy things… like the day when there will be a miraculous cure for retinal detachments without having to go through multiple surgeries and deal with sometimes crippling anxiety about repeat detachments.

The paranoia of the past couple of weeks started when i parked my car one sunny saturday morning and looked up at the blue sky, blinked, and saw a grey circle hovering threateningly in the sky.  I blinked again and it was gone.  Closed my eyes, opened them, and there it was again.  Blinked, and it was gone.  I must have sat there in the car for a good twenty minutes doing this like some kind of lunatic, before I noticed that there was a circular sign just in front of the car with a white border.  I now *think* that what I was seeing was a kind of after image of this.  I spent the rest of the day at various points stopping dead, staring up at blue sky and blinking, but I didn’t see it again.

I’d just about pacified myself over that, when the headaches started.  Every few days.  Not bad, but enough to feel pants and irritable.  I started to think it must be my eye pressure going up, so I went off to the opticians to get the pressures checked.  18 in both eyes.  Pheeeeew!  That was okay then!  So what was causing the headaches?  Increased hours at work?  Insomnia?  Stress?  All three most probably…

The headaches have improved over the past few days (I hope I don’t jinx it now), but my current paranoia involves looking right then left again, convinced I can see something pulling at the edge of my vision.  I have had this before many times and asked about it at many of my appointments and am always told it’s okay.  I even went and got my little eye book out the other day to check what’s been said about it in the past in the hopes that it would make me feel a bit better.  I’ve never received a satisfactory answer about what exactly it is, but have been told ‘it could be the oil’.  It seems I’m often told ‘it could be the oil’ when they’re not sure what it is.  A bit like going to the GP and being told that you have ‘a virus’.  But until I can ask about it again, it’s worrying me.  Plus I seem to be getting some more flickering in a different area of my eye.  I’m hoping this isn’t more of the retina starting to detach, as is the case with the almost psychadelic flickering which I often get at the bottom of my eye.  I keep obsessively checking my visual field against the various markers in my house, and at the moment, thankfully, it seems to be unchanged.  But I still worry, because I don’t know why it’s flickering.  My next appointment isn’t until 28 September, which seems an age away at the moment.  I fear I may be carted off in a straitjacket before that time.

I spy with my little eye something beginning with F…

…I stare in terrified concentration, heart thumping, at the black floater casually hovering against the pale wall.  The by now familiar sick feeling of please-don’t-let-there-be-any-new-symptoms rises in my stomach and my jaw clenches as I turn to look at a different part of the wall.  The floater disappears.  I turn my head back to the original spot.  There it is again.  I stare at it, whilst running through the options for emergency eye clinics in my head before the realisation dawns that it’s actually just a large fly on the wall.  I let out a huge sigh of relief as I feel my whole body relax, and the fly escapes a flattening due to my gratefulness that it isn’t a floater (although to be fair I’d probably miss anyway).

It’s this constant fear of any changes in vision and the possible symptoms of another detachment which is so difficult to live with.  I’ve jumped out of my skin at a blackbird swooping down in my peripheral vision, thinking it was a floater, burst into tears after seeing repeated camera flashes during a walk at dusk, thinking they were in my eye, and lain awake all night unable to sleep after seeing a flash on my bedroom wall because I couldn’t be sure whether it was external or internal.  Sometimes I close my eyes when the floaters in my good eye are driving me particularly crazy, only to find that I can still see some of them with my eyes shut.  I won’t even start trying to describe the weird kaleidoscopic lights and flashes you sometimes see in the dark immediately after surgery.  A few times I’ve started awake in a panic following nightmares that I’m having another detachment and had to switch the light on to make sure I can still see.  Since my most recent surgery I keep getting flickering at the bottom of my eye, but after my fourth surgery the flickering was at the top.  I think it’s to do with the areas which have been lasered but it can be hugely off-putting, as can what one RD patient described as the ‘lava lamp’ blob of light which occasionally scoots around the edge of my vision.

I have measurements for myself to test my visual field, depending on where I am.  If I sit at the table at my mum’s house and stare ahead at the door handle, I know that I should be able to just about see the light on the ceiling above if I look with each eye in turn, whilst keeping the other one closed.  I do the same in my own home, but sitting at the table and staring at the top piece of trellis out in the garden to check that I can still see the light above me.  At work, I stare straight ahead and check that I can see the top wall-mounted shelf through each eye.  When I had my third detachment with the oil still in, I couldn’t see the shelf at all.  I was excited when I returned to work after my third surgery and realised that I could actually see it again. Of course I’m well aware that doing this kind of thing makes me look either slightly crazy or possibly somewhat over-familiar because of the amount of winking which goes on, but I still find myself compelled to constantly check my vision in this way.  I’ve occasionally caught my work colleague gazing at me with a perplexed expression and had to explain what I’m doing.  Some days are worse than others, for some reason.  I have what I now call ‘paranoid eye days’, which are the particularly bad ones.  It’s comforting to hear from other people in the RD Facebook support group who report things like seeing a load of new floaters and then realising it’s actually ants on the wall, or jumping out of their skin because of flashes before hearing a clap of thunder following the lightening.  I was chatting to an eye buddy in the Netherlands a few weeks ago who said that sometimes she has to laugh at herself and what she must look like doing all the visual field checks, and other times it makes her want to cry because she doesn’t want it to rule her life.  We’re told by our surgeons to be vigilant and get any changes checked immediately, but this also makes us paranoid.  I don’t know what the answer is really, but if anyone has any useful suggestions, please let me know…