[aka HKGpax]
I am not sure how true this is, but I was told by a very senior (local Chinese) manager in Cathay that one of the reasons they have very few local flight crew is that CX requires all pilots to have near-perfect vision without the aid of any corrective devices. (I understand this is not the case for many airlines).
For some reason which is not fully understood, Hong Kong Chinese have one of the highest rates of short-sightedness in the world, so in fact few can pass the test once into their 20s/30s.