Mr Baker worked in a big factory. He was busy all the time and had little time to rest. One summer, he decided to go to the sea to spend his holidays. One afternoon, it was very hot. Mr Baker came into a restaurant, sat at a table and wanted to drink. Just then, an old man came up to him and said, "How do you do, sir?" "How do you do?" Mr Baker asked the old man to sit next to him. "Have you been here before?" "No, I haven't." "You look lonely, don't you?" said the old man. "Let's have a bet, shall we?" It interested Mr Baker, "But what shall we bet on?" "I can bite my left eyeball," said the old man, "I can bet you five dollars." Mr Baker didn't believe and passed $5 on the table. The old man took out his glass eyeball, put it into his mouth and bite it. Mr Baker had to give his money. "It doesn't matter young man," the old man said. "I'll give you a chance to win the money back. I can also bite my right eye. I'll bet you $10." "I'm sure he's able to see. And I must win his money," he thought. So he took out ten dollars from his wallet. But he was very surprised, the old man took out his false  teeth and bit his right eye with it. Then he put the money into his pocket and went away quickly. The old man was blind in   _  .
both eyes neither eye the right eye the left eye