Originally Posted by
ajax58
I note that both New Zealand and Canada accept the D15 as a second level assessment. Why can't CASA also accept this test? It's quick and easy to administer, and a lot less stressful for subjects (speaking from experience).
The answer,
in principle, is that the Australian rule prescribing the means of demonstration specifies only one second level test, namely the Farnsworth lantern. It's here at paragraph (b):
A person must demonstrate that he or she meets the criterion in item 1.39 of table 67.150 by:
(a) in daylight, or artificial light of similar luminosity, readily identifying a series pseudo‑isochromatic plates of the Ishihara 24‑plate type, making no more than 2 errors; or
(b) for somebody who makes more than 2 errors in a test mentioned in paragraph (a), readily identifying aviation coloured lights displayed by means of a Farnsworth colour‑perception lantern, making:
(i) no errors on 1 run of 9 pairs of lights; or
(ii) no more than 2 errors on a sequence of 2 runs of 9 pairs of lights; or
(c) for somebody who does not satisfy paragraph (a) or (b), correctly identifying all relevant coloured lights in a test, determined by CASA, that simulates an operational situation.
The
practical answer is that CASA AvMed picks and chooses the laws with which it strictly complies and those which it ignores and, due to inadequate governance, is allowed to get away with it.
For example, CASA AvMed treats the 'Optec 900' as a second level test, even though it's not prescribed. And CASA treated the CAD as a third level test, even though it does not simulate an operational situation.
My educated guess is that treating the Farnsworth D15 as a second level test would not suit the crusading CASA CVD zealots and their camp followers, precisely for the reasons you stated:
Farnsworth D15 is quick and easy to administer, and a lot less stressful for subjects.