I am the Guardian of the Gates, and since you demand to see the Great Oz I must take you to his Palace.

But first you must put on the spectacles." "Why ?" asked Dorothy.
"Because if you did not wear spectacles the brightness and glory of the Emerald City would blind you.

Even those who live in the City must wear spectacles night and day.

They are all locked on, for Oz so ordered it when the City was first built, and I have the only key that will unlock them." He opened the big box, and Dorothy saw that it was filled with spectacles of every size and shape.

All of them had green glasses in them.