In February of 1652, the English poet John Milton went completely blind. Many great artists have suffered blindness, but the twist in Milton's case is that he went blind before he wrote his best works, including the immortal epic poem Paradise Lost. Milton had written a few great poems before 1652, such as the elegy "Lycidas." But he was not a famous poet by this point.
In fact, Milton was more famous as a servant of the government of Oliver Cromwell, the "Lord Protector" of England during the period between the kings Charles I and Charles II. Without going too far into English history, we'll just point out that from the years 1649 to 1660, there was no monarchy. Charles I had been beheaded, and Cromwell turned the government into a republican commonwealth, which is to say, not a monarchy. Milton was a Puritan, and so was Cromwell. The 17th century Puritans believed that the Church of England needed to be reformed to create more distance from the elaborate ceremonies and power structures of Catholicism and the Pope. They wanted to boil Christianity down to the basics of "pure" piety and morality. Thus, Milton was a big-time supporter of the commonwealth government, and he used his incredible powers of persuasion on behalf of Puritan rule in essays published in pamphlets.
But, like we said, Milton went blind a few years after the Puritans gained power, and in this sonnet he worries about how he can serve God even with this condition. Many scholars date the poem to 1655 (source). When reading this poem, you have to keep in mind that Milton is not just using false modesty here, because he had not written the works that would cement his reputation. Hearing the author of Paradise Lost say, "I haven't accomplished all the stuff I wanted to!" would be like Tiger Woods complaining that his life was wasted because he had never won the world Sudoku championship. But that's not what Milton is doing in this sonnet – his "talent" at this point was still unproven.
Milton's blindness has become something of a myth. Some people think that Milton dictated all of Paradise Lost to his three daughters. And at least one scholar has suggested that he drove his daughters out of his house by making them read to him in languages they couldn't even understand (source).
When John Milton went blind, he must have felt like modern athletes feel when they suffer a career-ending injury. You spend your whole life working toward a goal, pour your heart and soul into practicing, and then some uncontrollable event or freak accident puts you back in the shoes of a regular guy. In the movie Friday Night Lights, the star high school running back Boobie Miles injures his knee and loses the chance to play for a state championship and earn a college scholarship. Things like this happen to people all the time, we just don't normally hear about them. The myth is that if you work hard enough, you can achieve anything. But, as many people have discovered, while you certainly can't achieve great things without working hard, the hard work is no guarantee.
John Milton's life plan was to be of service to God. He felt he could best achieve this goal by using his intelligence and especially his writing. But back when Milton was alive, it was very hard to write when you had no vision. He was entirely dependent on other people to write down his work and read to him. Fortunately, Milton's blindness was not as crippling as he thought it would be, and he eventually adapted to the condition enough to write some of the world's great works of literature.
This poem shows, though, that outcome was far from a sure thing. This sonnet puts us in the shoes of someone with enormous talent who must suddenly accept a new purpose in life. He goes from being a mover-and-shaker to being someone who merely "stands and waits" on God.
John Milton's poem, "On His Blindness," speaks to the frustrations Milton had regarding his lost sight. The poem reflects upon the idea that he (the speaker of the poem) will not be able to serve God now that his sight is gone. The following will show each line of the poem (or relevant groups of lines) and the meaning of the line/s following.
WHEN I consider how my light is spent,
The speaker is reflecting upon how his light (sight) has been used over his life. This could also refer to the speaker's spiritual light (given Milton's religious ideology).
Ere half my days in this dark world and wide,
The speaker has spent half of his life blind (meaning he knows what it means to see and feels loss at his sight being taken away).
And that one talent which is death to hide
Here, the talent the speaker refers to can be his ability to write (which may be lost now that his sight is gone), or it could refer to the God-given talents bestowed upon mankind by God.
Lodged with me useless, though my soul more bent
The speaker feels that his loss of sight has left him useless (to either write or serve God).
To serve therewith my Maker, and present
My true account, lest He returning chide,
'Doth God exact day-labour, light denied?'
There three lines refer to the speaker's desire to write and praise God, but, with his lost sight, he feels as if he cannot do either. (The speaker's writing could be referring to his desire to write for God.) The speaker is asking if God expects him to work given his light (sight) is gone.
I fondly ask.
Here, the speaker is asking for guidance in regards to how he should approach his concerns (his inability to write and write to praise God).
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.'
In these last lines, the speaker receives the reply he has asked for. Patience replies to the speaker (given his patience with his blindness is lacking). Patience replies that it is not the work of man which pleases God. Instead, it is the "mild yoke" (those who are simply obedient to God) which makes God happiest.
For patience, God is happiest when mankind is able to spread God's word over "land and ocean without rest." The final line refers to the fact that it is far more important to praise God than to "stand and wait" (do nothing).