Explain the meaning of, “Alack, there lies more peril in thine eye than twenty of their swords.”from Romeo and Juliet

Much of Romeo's character is on display with this line. 
The idea of setting up the look in Juliet's eyes and "twenty of their swords" helps to
enhance the fundamental conflict in the romance of the two young lovers.  Romeo is
poised between difficult and competing ends in the look in her eyes and the swords that
represent her name.  At the same time, Romeo is trying to convey how he values her,
Juliet, more than anything else.  The language of "peril" in a look that she gives him
is interesting.  This "look" can be one of disapproval, reluctance, hesitation, but it
is something upon which Romeo places heavy weight. The idea of Romeo's impulsive
behavior and his propensity for hyperbole is also evident in this statement.  The fact
that Romeo claims through language that he is willing to ensure "twenty of their swords"
to one look from Juliet helps to convey both his indulgence in emotions and his
hyperbolic and intense view of the world.  This is a sign to both Juliet and the reader/
audience that Romeo's roller- coaster of emotions can dip into the realm of the
destructive, something that foreshadows what is to come in the
drama.