Commando Officers who wore glasses during WW2

I was wondering why there has been a turn around in the present day military concering the wearing of glasses. Ive observed many photos of ww2 army officer commandos wearing glasses, yet in todays modern Royal Marine commando they wont have officers with poor vision.

Does anyone know what the entry requirments during WW2 were concerning eyesight? Are the men I am observing mearly border line cases that were allowed to pass under less strict WW2 conditions?

Can anyone please explain?

Thank you,

Steve.