https://www.casa.gov.au/licences-and...equently-asked
Australia is more flexible in its approach than other countries in allowing applicants to sit multiple sequential tests for CVD where a fail is recorded and a medical certificate can be issued if at any stage any of the three-level tests are passed. Most overseas regulators do not allow this level of flexibility.
The procedures are:
Initial issue of class 1 medicals
Applicants for a Class 1 Medical Certificate must either satisfy the criteria specified in CASR 67.150, or be found by CASA not to pose a danger to safety on account of their CVD. To satisfy the requirements of CASR 67.150, the applicant must first attempt the Ishihara test. If they fail that test, they must then undertake the Farnsworth Lantern test. If the Farnsworth Lantern test is also failed a third level of test specified (for the individual case) by CASA must be undertaken. Failure of that third-level test may allow for the issue of a medical certificate if CASA finds that the applicant's CVD does not pose a danger to safety. A Medical Certificate issued on this basis will be subject to certain limitations or restrictions.
Initial issue of class 2 medicals
If the Ishihara test is failed, a certificate will be offered restricted to day VFR only. If the applicant wants this restriction removed, they must pass one of the tests as per Part 67.
Class 1 medical renewals
No immediate change. CVD Class 1 pilots may need to undergo a CAD test in the future.
Class 2 medical renewals
No immediate change.
Air Transport Pilot Licence applications
A certificate will not be issued until a test has been passed as per the existing regulatory requirements.