In “The Merchant's Tale” and the story's prologue, Chaucer both incorporates and critiques ideas of courtly love and romance. In the prologue, the tendency is far more toward critique. The Merchant has only been married two months, and he is miserable. His wife has a sharp tongue and a nasty disposition. She is cruel, filled with malice. There is nothing even close to a courtly romance in the relationship between these two spouses, and the Merchant is severely regretting his choice to marry. Those who complain of being wifeless should not, he implies, for marriage just brings sorrow.
The Merchant proceeds, then, to relate his tale. A wealthy old knight named January wants to marry. He believes that it is God's will for him (notice the courtly element here with the incorporation of a divine). His friends try to tone down his romantic ideas about marital bliss, reminding him that wives are expensive and actually make life much worse. But January sets his eye and his heart on a young lady named May and marries her, hoping that she will be his help and comfort and make his life a paradise on earth as they become one flesh and one heart. Indeed, January is fully caught up in the courtly ideal.
Unfortunately, only a little time passes before January's attendant, the handsome young Damian, also becomes enraptured with May. His love makes him physically ill (another courtly theme). January makes a big mistake when he sends May to comfort Damian, and the two young people declare their undying love for each other. Here, again, is courtly romance in action. Forbidden love is all the sweeter, after all.
At this point, January unexpectedly goes blind and insists that May remain with him at all times. May has no opportunity to be with Damian until she schemes to meet him in the garden with the blind January in tow. Things quickly turn quite graphic (not at all courtly at this point), and January's sight suddenly returns. His wife manages to convince him that he didn't see what he thinks he saw, and January loves her just the same. He is no longer physically blind, but he is certainly still blind in his love.