Discuss the use of light by Tennessee Williams in his play a Streetcar Named Desire.

Tennessee Williams is renowned for his use of stage and lighting to convey underlying themes during his plays and his use of light in a Streetcar Named Desire is no different.
For a question like this, it is best to brainstorm any ideas you have about:
Whether light has any affiliations to certain characters?
Does the motif appear at certain points in the play? If so, track the points at which light appears, there may begin to be a pattern which will help develop your ideas.
Look into what Williams may be using light to represent.
You should aim to get between 3-4 key ideas, 5 at the maximum. With an A-Level English essay, the aim is not to get down as many points as possible but to develop points in a sophisticated and evaluative manner that ties in all of the key AOs e.g. context and literary interpretations. Examples of a few points that can be made:
Williams uses light to represent truth within the play, in particular Blanche's fear of the truth about her being revealed or her own fear of facing reality.
William's use of light to represent Blanche's past and how Blanche's fear and attraction to light represents how Blanche desires a return to her former self.
Blanche's desire to hold onto the past seen by her attraction to light will be her downfall. William's engages with the moth motif - a moth is attracted to light but this can also serve to kill the moth. Blanche's desire to hold onto the past, ignore reality and create illusions is what will lead to her downfall.
Stella's name means star in Latin, another light symbol. It is Stella who eventually sends Blanche away to the mental asylum. Does this mean that it was the light and its symbolisation of truth that eventually destroyed Blanche, or is Williams alluding to a different meaning of what light symbolises in the play?
There is an overarching theme through all of the above points and that is the idea of light representing truth or reality and Blanche's desire to fabricate the truth and create her own illusion. The first point shall be explored. If you struggle with creating a point, use the PEAL structure: point, evidence, analysis and link. Students often fear that this will make answers mechanical but PEAL is only meant to be used as a basis to help you develop your own writing style. We shall look at the first point:
Williams uses light to represent truth within the play, in particular Blanche's fear of the truth about her being revealed or her own fear of facing reality. Throughout the play, Blanche's fear of light can be seen: she buys a paper lantern to put over the exposed lightbulb in Stanley's living room, she will only go out with Mitch in the evening and even says 'the dark is comforting to me.' Williams can be seen as using light to symbolise the truth, in that Blanche's greatest fear is that the lies that she has told will be exposed and her use of the paper lantern over the bulb is to hide the truth. Blanches wishes to create an illusion of what she wants the truth to be, which she says so herself to Mitch, 'I don't want realism, i want magic.' The truth is that Blanche is not Stella's younger sister, she is in fact older and she is not the pure Southern Belle she has portrayed herself to be. She has a promiscuous past which she believes will make her undesirable to men. Williams was highly influenced by Southern cultural values being a Southerner himself and a Southern Belle was desirable because she was youthful, chaste and innocent - all of which Blanche is not. Blanche's need to be what she once was leads to her desire to cover the bulb with a paper lantern. The paper lantern over the bulb represents Blanche herself, Blanche wishes to hide from reality so she decorates her life with illusions and lies but the paper lantern is a flimsy protection, just as the lies hiding the truth are very easily torn down. When Mitch angrily tears the paper lantern off and exposes the light Blanche cries out, as this symbolises not only that the truth is exposed, but that she must herself see her own reality in all its tragedy.