What is My Eye?
1.
a friendly, acceptable way to express disagreement with the previous speaker's statement.
It is the root phrase behind more vulgar terms replacing the keyword "eye" with other parts of the human anatomy less suitable for a wide audience.
high schooler #1: My '95 Grand Am is so fast! It does 0-60 in 7 seconds flat!
high schooler #2: My eye, Steve.
See
