The speaker admires someone else's eyes and wishes to have them. The poem is dedicated to "Iris," which also happens to be the name for the colored part of the eye, so the name quietly ties the whole thing together. What the speaker wants is a way of seeing that picks up what most people miss, "the unseeable."
The second half turns that seeing into a picture. Those eyes follow thin lines across sheet after sheet of paper, as if drawing or writing, until the pile topples and the pages scatter into the wind. The speaker doesn't seem upset by this. The pages "dance," which makes the collapse feel more like release than loss.
The mood is wistful but light. There is longing in the opening wish, then a gentle freedom at the end. The poem suggests that deep attention and creative work don't have to stay neatly stacked; they can be let go.