When the travelers finally arrive at the gates of the Emerald City, they are asked by the Guardian of the Gates to wear green tinted spectacles to keep their eyes from being blinded by the city's brilliance and glory.
When the travelers finally arrive at the green marble gates of the Emerald City, they are asked by the Guardian of the Gates to wear green tinted spectacles before stepping inside. This is to keep their eyes from being blinded by the city's brilliance and glory.