So has there been a spate of accidents caused by pilots who aren't carrying a spare pair of glasses, or by the spare pair not correcting the pilot's vision sufficiently?
Why would a pilot, who's silly enough to fly without an adequate spare set of glasses, stop doing it just because once a year or once every two years the DAME makes him or her do an eye test using two different pairs of glasses?
Strikes me as just another manifestation of Avmed's messianic delusion that it's the last bastion between dangerously stupid and sick pilots and the travelling public.
Arseclowns.