Read the story and answer the question.

Once upon a time, there was a wealthy woman that had very poor eyesight. She decided to call a doctor to ask if he could restore her eyesight. The doctor promised to cure her but told her that she had to pay him a huge fee. He also told her that throughout the treatment she had to keep her eyes closed. The woman agreed to both requirements.

The doctor began the treatment in the women’s home. Every day the doctor stole something from the lady’s house. The treatment lasted a lengthy period of time. Finally, when he had emptied her house, the doctor told her that he had finished her treatment, and that eyesight was restored.

The woman was very happy that the treatment was over, but she refused to pay the doctor. The doctor was very angry that she refused to pay his hefty fee. He told her that he was taking her to court. She just laughed at him.

When the judge asked the woman to explain why she didn’t pay the doctor, the woman said, “Sir, before the operation, I was partially blind, but at least I could see the things in my home.” She continued, “But now after the treatment, I am unable to see anything in my home. The woman solemnly told the judge, “I must be totally blind because I can see nothing.”

The judge looked at the doctor, who hung his head in shame. He realized that the woman knew that he had stolen all her things. He felt ashamed and returned everything he had stolen. The doctor also said that the woman did not owe him a fee for the treatment.

Why did the doctor tell the old woman, “You must keep your eyes closed during the treatment"?