ON HIS BLINDNESS

When I consider how my light is spent
Ere half my days in this dark world and wide,
And that one talent which is death to hide
Lodg'd with me useless, though my soul more bent
To serve therewith my Maker, and present
My true account, lest he returning chide,
"Doth God exact day-labour, light denied?"
I fondly ask. But Patience, to prevent
That murmur, soon replies: "God doth not need
Either man's work or his own gifts: who best
Bear his mild yoke, they serve him best. His state
Is kingly; thousands at his bidding speed
And post o'er land and ocean without rest:
They also serve who only stand and wait." 

ANALYSIS

The first element that the intelligent reader should notice is the title. The key word in the title is the term "his", it informs the reader that the subject of the poem must be a person, and ,in particular, a man. One more word of relevant importance that is presented in the title is the term "blindness", it suggests  that the subject of the poem is blind.

Observing the layout, the intelligent reader notices that the poem consists of 14 lines, so it's a sonnet. Observing the punctuation, the sonnet can be organized into an octave  and a sestet and the intelligent reader should notice that is the structure of the typical Petrarchian sonnet.

The octave bears the problem:  the speaking voice is becoming blind, because "his light is spending", and he is wondering how can he serve God with his blindness. The sestet bears the solution of the problem, by saying that "God doth not need Either man's work or his own gifts: who best Bear his mild yoke, they serve him best.