“In the land of the blind, the one-eyed man is king!”

I understand the quote is attributed to Desiderius Erasmus Roterodamus, or Erasmus of Rotterdam, a 16th-century Dutch Renaissance humanist. He was also a social critic, Catholic priest, teacher and theologian.

The quote is an idiom.

The basic idea is, if surrounded by people less capable or able, someone who would not normally be considered special can shine.

The quote is common in different languages, including German and Italian. According to Good Reads, the idiom has been used widely for political and social commentary.

It is also commonly linked with the 2006 film “Land of the Blind,” a political satire.

References

http://www.goodreads.com/quotes/93660-in-regione-caecorum-rex-est-luscus-in-the-land-of. [Accessed: 10 July, 2017].

https://www.usingenglish.com/reference/idioms/in+the+land+of+the+blind,+the+one-eyed+man+is+king.html. [Accessed: 10 July, 2017].