What is the "Truth" of "The Eye of the Beholder?"

My opinion:
The truth of this episode of the Twilight Zone is that being different is a crime.

How does the filmmaker reveal this?

My opinion:
The filmmaker reveals this by using tone. In the episode, the woman had an angry tone because the "normal" people did not accept the way she looked.

What is the theme of the episode?

My opinion: 
The theme is that everyone is beautiful, but they just need to know and own it.

How does the filmmaker reveal this?

My opinion:

The filmmaker revealed this by using visuals. The episode showed the difference between everyone else and the woman. When the guy that looked just like her said,"Beauty is in the eye of the beholder," it made her realize that she is beautiful in her own way.