2017-10-19

Understanding what I can see

I often struggle to explain to people what I can see in what situations, so the best way to explain this is to show you is with some pictures that I have created that describe what I see in various situations.

The eye conditions that I have are :

  • Bilateral moderate myopia
    • short sighted in both eyes
  • Bilateral congenital cataracts
    • born with cataracts in both eyes, a problem to do with development of the eyes of the foetus in the womb.
    • in left eye the cataract is central, causing spatial distortions and rendering the eye useless for reading or anything except peripheral vision
    • in the right eye the cataract is off to one side so does not cause the spatial distortions
  • Deprivational Amblyopia / Lazy left eye
    • because of the central cataract my left eye didn’t develop normally
    • this is better known as causing double vision.
  • Bilateral pigment dispersion syndrome
    • the iris colouring is falling off, floating into the eye and blocking the draining canal, which builds up the pressure, which leads to glaucoma.
    • moderate myopics are more prone to this apparently.

There are many situations that my eyesight causes me problems, but as I spend most of my time in front of a computer, I’ll start with that one … the others will appear as time goes by.

At my desk

I’ve spent a little bit of time putting together some images to help illustrate how it affects my day to day job … it’s not a huge impact … but it has some consequences that I do endeavour to work around and appear to be as ‘normal’ as possible … even though I’m very much at the thin end of that bell curve.

My monitor set up is two 24inch wide-screen monitors (DELL U2414M) lying horizontally but the pair aligned vertically centred to the middle of my right eye. I sit with my right eye vertically in the middle of my upper monitor about 3/4 of the way down the screen if I look straight ahead with my eyes. My eye is about 20cm away from the screen at the nearest point.

I’ve captured the screens without any effects (apart from obscuring sensitive information), I believe is what you would see if you could see both screens in focus all at the same time … I don’t know whether that is what 20/20 vision people are able to see when they look at their monitors … maybe someone could comment … I appreciate that our brain focuses on a small area and the rest becomes blurred to some extent … but how much others can see and read at once without moving their eyes from the focussed area I don’t know.

I’m going to show you what I can see if I focus on the token ‘printerName’ highlighted in the code snipped in the image above with a yellow eliptical(-ish) highlight on the screen.

If I close one eye at a time and [try to] look at the word ‘printerName’ in that yellow highlighted area … the two pictures below show what I can see with my eyes individually if I try to take in the whole picture without moving my eye. The white and blue areas in the lower screen really become solid blocks of white with a blue line above … but I can vaguely make out that it is not solid colour.

Having seen both eyes separately, you obviously know that our brains will attempt to combine the images from both eyes into one 3D view.

So, if I open both eyes and try to view the screens normally then I see something similar to this with my brain … the distortion that I get with the left eye comes and goes depending on how long I’ve been looking at the screen … it is there when I initially look at the monitor and fades out the longer I concentrate on the text with my right eye.

I do see two images that do not align and I mostly notice this on the left hand side (when I look towards my nose with my right eye)

A reason I wear headphones a lot … imagine notifications popping up in the far corners of the screens … or for Skype for Busiess which seems to popup in the background behind other windows … that’s why I don’t see them … but I can hear them if I wear the headphones.