How does Death of a Salesman reinforce the theme of illusion within the play?

Illusion
is addressed constantly within s play. One aspect might instead be called delusion, as several
of the characters are operating with fantastic ideas about what constitutes real life. Willy
Loman and his sons are weighed down by the illusory dreams they once had but which have escaped
them. Willy, in particular, clings to the vision of what his sons might have accomplished. This
backward-looking vision affects their relationship; because he cannot accept who they are, he
seems constantly disappointed, and Biff and Happy both resent his critical attitude. The blurry
line between reality and illusion grows even weaker as Willys mental health deteriorates. The
audience is often unsure whether he is remembering things that actually happened or fantasizing
about things that did not. The author uses dialogue and monologues to show the progression of
Willys decline, as he increasingly intersperses speech about contemporary life with these
memories, such as addressing people who are not there.

The plays original,
highly innovative staging also emphasizes illusion. Parts of the Lomans house are insubstantial,
and lighting is used to create effects of solid walls or to make them transparent and then
vanish. Miller explained that in the current time period, the actors observe the imaginary
wall-lines, but in the past, they can step right through the walls made of
light.