Here in Hawaii (Big Island) and applying through the VA (have to get authorization still) glasses have been available each year so far, or if vision changes (a few times now) or they make a mistake (which has happened). Two years is a long time to keep glasses in good condition for anyone--especially since the frames are flimsy.
Diabetes and all kinds of service-connected illnesses or trauma can affect vision besides aging and so this sounds like they are just needlessly making things tough for veterans, healthy or disabled.
Good luck with your ultrasound.