How does Adam Thorpe portray the effects of disability in 'On Her Blindness'?

In his poem 'On Her Blindness,' Adam Thorpe portrays the effects of disability on the speaker of the poem and his mother, who goes blind but is unwilling to acknowledge the effects of her handicap due to her independence and pride. The poem ends with her death. Thorpe portrays the emotional distance created between the speaker and his mother, and also presents the attempts of the mother, and perhaps her son as well, to control and contain her blindness.
In the title of the poem, Thorpe alludes to the sonnet 'On His Blindness' by John Milton, in which Milton meditates upon his condition after going completely blind. Primarily, this title establishes a sense of emotional distance between the speaker and his mother. The use of the pronoun 'her' is impersonal and neutral, and the literary allusion creates a sense of intellectual detachment, keeping the poem from being immediately identifiable as a highly personal subject. Thorpe also suggests this distance throughout the rest of the poem, as the speaker refers to himself as 'inadequate' and as 'the locked-in son.' Thorpe makes use of humorous imagery such as the mother 'bumping into walls like a dodgem,' suggesting that the 'locked-in' speaker is mirroring his mother's strategy of 'laugh[ing] it off,' presenting their methods of dealing with her blindness as perhaps equally ineffective: he is unable to comfort her or to contradict her denial of her loss of sight. This is exemplified in the interaction that Thorpe portrays at the end of the poem, in which even if the speaker does address more personal topics, all we hear him discuss is the weather outside. His mother responds ''Yes, I know,'' maintaining her pretence to the end, even in front of her own son, and therefore emphasising the distance between them.
Secondly, to return to Thorpe's allusion to 'On His Blindness,' which portrays the thoughts of a speaker on his own blindness, it is interesting that in Thorpe's poem, the speaker is not the person who is going or has gone blind. This suggests that the speaker is meditating on his mother's blindness for her. This implication is ambiguous: it could emphasise the mother's refusal or simple inability to acknowledge her blindness, leaving her son to speak about it in her place, or it could suggest that the speaker is trying to contain the painful reality of his mother's blindness by reframing it in his own terms. This latter interpretation could be supported by Thorpe's structural choices in the poem. 'On Her Blindness' has an even, regular structure of stanzas which are almost all couplets, but Thorpe frequently makes dramatic use of enjambment within this structure. For example, the enjambment in phrases such as '(try it / in a pitch black room)' or 'when cast / inward' creates a sense of being off-balance, evoking the mother's experience of trying to live normally while blind. But this uncertain, unbalanced tone is contained within a very, balanced, regular structure. This could suggest the mother's attempts to conceal her blindness and continue with her life as normal, despite these attempts being constantly undermined, as in the line 'sink into television / while looking the wrong way,' in which Thorpe portrays the mother performing a normal activity and then immediately undermines this image with the reveal that she is not looking at the television. However, it could also be a result of the speaker trying to speak for his mother, as we potentially observed in the title of the poem, and to describe her blindness in a way that maintains emotional distance from the 'catastrophic' reality of her blindness - a reality of which he is well aware.
To conclude, Thorpe uses allusion, structure, and diction to portray the effects of disability in 'On Her Blindness.' He suggests both an emotional detachment between the speaker and his mother that seems to be exacerbated by her disability, and also suggests that either the speaker, his mother, or both attempt to control, contain and even ignore the effects of her disability.