In a training session for new recruits, a senior police officer tests their skills - he shows the first guy a picture for 5 seconds and then hides it. "This is your suspect; how would you recognise him?" says the senior officer.
The first guy answers, "This is easy, we will catch him fast because he only has one eye!" The policeman says, "Well...uh...that is because the picture I showed is his side profile."
Slightly flustered by this ridiculous response, the officer flashes the picture for 5 seconds at the second guy and asks him, "This is your suspect, how would you recognise him?"
The second guy smiles, flips his hair, and says, "Ha! He would be too easy to catch because he only has one ear!"
The policeman furiously responds, "What is the matter with you two?? You can only see one ear and one eye because it is the suspect's side profile! Is that the best answer you can come up with?"
Extremely frustrated at this point, he shows the picture to the third guy and in a very testy voice asks, "This is your suspect, how would you recognize him? He quickly adds, "Think hard before giving me a stupid answer."
The third guy looks at the picture intently for a moment and says, "the suspect wears contact lenses."
The policeman is surprised and speechless because he really does not know himself if the suspect wears contacts or not.
"Well, that's an interesting answer. Wait here for a few minutes while I check his file and I'll get back to you on that." He leaves the room and goes to his office, checks the suspect's file on his computer, and comes back with a beaming smile on his face.
"Wow! I cannot believe it. It's true! The suspect does, in fact, wear contact lenses. Good work! How were you able to make such an astute observation?"
"That's easy," the third guy replied." He cannot wear regular glasses because he only has one eye and one ear."