Thursday, 18 March 2010

Feeing sick or giddy when you read

The last blog I wrote said that I would write about this next. A lot of people get this feeling when they read. For many it only happens when they are reading in a ca, bus or train.
When you put an Eyetracker on someone who feels giddy after a while of normal reading you can see that, their heads are moving a lot as they read. Often these people tell me that they get a stiff or aching neck after they have been reading. Or they get aches in their back!
One exceptional case was a lady who was a senior manager with a major organisation in the UK. I was called in because her head movement had got really severe, giving rise to medical intervention and damage to her neck vertebrae! She was feeling really bad after working on her computer for only a short period it really affected her productivity.
Again using the eye tracker, confirmed what you could actually see as she read. Sh3e showed the characteristic eye movements of someone, who for some reason had become extremely light sensitive.

The first thing was to look at ambient light issues. It was amazing what a pair of wraparound dark goggles did for her. But it only partially solved the problem...
By the time we had got the screen to the right low level of brightness, and got the red: green balance right for her she was in ‘reading heaven’. The health and safety people reduced the brightness of her workstation area.
She was very quickly working at highest level again...

You can pin the giddiness down to the effect on your balance system of the head movements needed to read on white. It is A bit like sea sickness, or travel sickness. It is linked to a thing referred to as the ‘vestibular-ocular reflex.’ The mechanism which allows you to fix your eyes on something even when your body is bouncing up and down as you walk.
We did not evolve to read! Our ancestors did not do it! There is no reading gene!
So sitting still and concentrating on reading for hours is really quite unnatural...
Certainly staring at black lines on a white page is as natural as staring at the black lines on a zebra.
On a zebra it is intended to mess with the eyes and head of the predator. It is sometimes referred to as ‘pattern glare’...
It creates the illusion that the lines/words are moving.

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