The European Aviation Safety Agency said all pilots should also "undergo psychological evaluation" during training or before entering service and face random drug and alcohol tests, although investigators have not cited them as factors in the Germanwings tragedy.
Investigators say that 27-year-old German co-pilot Andreas Lubitz, who had a history of severe depression, intentionally slammed the Airbus A320 into the French Alps.
They said he locked the other pilot out of the cockpit when the latter went to the toilet on the flight from Barcelona to Duesseldorf on March 24 and then put the aircraft into a steep dive as his colleague tried desperately to get back in.
Several of these doctors who were questioned by German investigators said Lubitz complained he had only 30 percent vision, saw flashes of light and suffered such crippling anxiety he could barely sleep.
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Lubitz reportedly said "life has no sense with this loss of vision".
However the doctors he consulted -- including one who booked him off work two days before the ill-fated flight -- did not reveal his mental struggles due to doctor-patient confidentiality rules.
Many European airlines already enforced such a measure before the crash and others have adopted it since.
After a three-month review ordered by the European Commission, the EU executive arm, EASA confirmed the recommendation and said it would look at the situation again after a year.