PPRuNe Forums - View Single Post - The Empire Strikes Back! on Colour Defective Pilots
Old 14th Jul 2014, 11:06
  #380 (permalink)  
Arthur Pape
 
Join Date: Jul 2007
Location: Australia
Age: 78
Posts: 50
Received 18 Likes on 5 Posts
I apologize, 4Dogs, for giving the impression that I was accusing anyone of corruption; such is far from the truth.

From 1977 onwards I was a close observer of the research work originating almost exclusively from the Vic College of Optometry. I was able to obtain via a FOI request a great deal of the correspondence between the regulator and the VCO, and the terminology was often along the lines of "defending the standard". Bias can arise from the terms of the contract between sponsors and researchers.

Contrary to your assertion regarding the suppression of the optometry school by the ophthalmologists, I found the exact opposite. I challenge any observer to find a published paper by any individual or collection of ophthalmologists on the topic of the aviation colour perception standard. In fact, in my dealings with them, I found most ophthalmologists were quick to acknowledge how little they knew about colour vision defects. I find the same today.

In 2002 there was a heated debate that played out in the pages of "Clinical and Experimental Optometry" between Dr Richard Wolfe, the Chairman, Visual Standards Committee, Royal Australian and New Zealand College of Ophthalmologists, and a number of optometrists representing the College of Optometry. The debate topic was "Protans and Driving Safety" and the problem Dr Wolfe saw was the selective and inappropriate interpretation by the optometrists of published road accident data. Reading the same papers, Dr Wolfe came to the opposite view in regard to accident rates for colour defective drivers. The view of the ophthalmologists ultimately prevailed and the colour vision standard for road transport was subsequently abandoned Australia wide. I refer the reader to Clin Exp Optom 2002; 85: 6: 399-402. The same Dr Wolfe admits freely how little he knows about colour vision defects, but that was not the issue. The issue was, with close parallels to the current aviation colour vision debate, how a certain group mindset can predispose to a bias that is unlikely to be detected or exposed from within that group.

Optometry is but one of many disciplines within the broad field of the visual sciences . Until I got seriously into my own reading, I had never heard of the field of perception psychology. I too believed the eye was a camera and the brain something akin to a computer. I now know that human perception is far more amazing than what any such simple analogy can describe.

The common theme in much of the research presented to the AAT 25 years ago was the reduction of complex psychomotor tasks to the level of de-facto colour vision tests. People with colour vision defects are distinguished by their inability to pass colour vision tests, and experiments that reduce the task to a colour vision test will inevitably produce predictable results. The best illustration of this phenomenon is embodied in the two papers: MacDonald and Cole, in Ergonomics 1988, and Cole and MacDonald, in Opthal. Physiol. Opt.,1988 Vol 8. The first papers sought to determine the value of colour coding in the new technology of the day, the EFIS displays of the B767. The second measured the performance of colour defective observers against the performance of colour normal. The bias built into this paper was palpable, once it was realised that the colour normal subjects were sourced from the student ranks of the College of Optometry. Their mean age was of the order of 23 years. The colour defective subjects (from memory, four different groups) were sourced from the public patient lists of the College, with significantly greater mean ages and lower levels of academic backgrounds. None were pilots and all had brief indoctrination in the meaning of the various colour coded symbols that they would be expected to identify in a multiple choice task. What they were administered amounted to quasi colour vision tests. The results were a foregone conclusion. The design of the experiments was flawed at several levels, yet both papers passed through the peer review processes and were judged suitable for publication. Not a word of critique was subsequently ever sighted in the journals concerned. The critique of these papers in particular in the AAT was a lesson in basic experimental design and how not to do it.

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