This old man was a witness in a burglary case.
The defense lawyer asks Sam, "Did you see my client
commit this burglary?"

"Yes," said Sam , "I saw him plainly take the goods."

The lawyer asks Sam again, "Sam, this happened at
night. Are you sure you saw my client commit this crime?"

"Yes" says Sam, "I saw him do it."

Then the lawyer asks Sam, "Sam listen, you are 80 years
old and your eye sight probably is bad. Just how far can
you see at night?"

Sam says, "I can see the moon, how far is that?"