The context of the text is laziness. In v. 6, Solomon tells the lazy person to look to the ant. The ant has no boss telling her what to do. But she prepares her bread in summer. She gathers food for the winter—when food is lacking. The ant is a picture of diligence—the opposite of laziness.
In v. 9, Solomon asks the lazy person how long will he lie there? Then in vv. 10-11, the wise man says that a little sleep leads to poverty. It does not mean that we should no longer sleep and rest. Sleep here symbolizes laziness in preparing for the future. It is not just laziness or doing nothing, but also, laziness in preparing for tomorrow.
“Love not sleep, lest you come to poverty; open your eyes, and you will have plenty of bread” (Prov. 20:13). In Prov. 20:13, poverty is contrasted with plentiful food. Sleep is compared to the opening of the eyes. Thus, to sleep is to become poor, i. e., to lack food. Sleeping leads to poverty. Sleeping is thus a metaphor of laziness. To open the eyes, however, is to have plenty of food. Opening one’s eyes, therefore, is a metaphor of diligence.