"A Lover's Eyes Will Gaze An Eagle Blind"
Context: At the first part of the play, several men pledge with the King of Navarre to study for three years and to abstain from any contact with women. Berowne, one of the lords attending the king, is the only one in the group who expresses doubt as to the wisdom of the second part of the vow. Later, after he is proven correct when all of the group have fallen in love, he explains and philosophizes on the benefits of love. He emphasizes repeatedly the fact that love makes all the senses alert "And gives to every power a double power." Thus the eyes of a lover will be increased in their ability to see with more scope and comprehension the world around them.
BEROWNE. . .But love, first learned in a lady's eyes,Lives not alone immured in the brain,But with the motion of all elements,Courses as swift as thought in every power,And gives to every power a double powerAbove their functions and their offices.It adds a precious seeing to the eye:A lover's eyes will gaze an eagle blind.A lover's ear will hear the lowest sound,When the suspicious head of theft is stopped.. . .