Doctor, you say there are no haloes
around the streetlights in Paris
and what I see is an aberration
caused by old age, an affliction.
I tell you it has taken me all my life
to arrive at the vision of gas lamps as angels,
to soften and blur and finally banish
the edges you regret I don't see,
to learn that the line I called the horizon
does not exist and sky and water,
so long apart, are the same state of being.
Fifty-four years before I could see
Rouen cathedral is built
of parallel shafts of sun,
and now you want to restore
The poem switches focus. The subtopic (although the main topic remains light and perception) switches briefly to the topic of age, which was also briefly mentioned in the beginning of this poem. 
 The word “see” makes an appearance at the end of the sentence, which in the past has proven a hint at the importance of the following line.
Monet Refuses the Operation