One “eye-dea” per phrase is a way to help you remember that we show that we are having a new idea by shifting our eyes. It is also to remind you that just like we have one music phrase per text phrase we should have one body language phrase per phrase.
This means that if we shift the direction of our eyes more than once in a phrase, or don’t shift our eyes to start to show what we are talking about next then the body language, music, and text will no longer be communicating the same thing. Consequently, the audience will subconsciously identify that something is off and disconnect from the performance.
What happens if we have more or less than one idea per phrase
If we shift less than one idea per phrase it reads that we are braindead, depressed, or disconnected from what we are saying.
If we shift more than one idea per phrase it looks like we are crazy or on some kind of illicit drug. Think of someone with “shifty eyes”. This is usually a sign that someone is having more ideas than their mouth can keep up with.
These are tools we can read if we have a character who is supposed to be behaving unlike a normal relatively healthy human being. If you are supposed to be playing a mentally slow character, or a crazed character now you know how to start going about showing that.
For most characters on stage, we want to learn to stick with just one eye-dea per phrase. The challenge with this is that as a singing performer there often are multiple thoughts running through your head during a single phrase as you are performing. Ideally, you would have rehearsed each element well enough that you can just focus on being the character and thinking their thoughts and feelings but that isn’t always reality. The important skill to learn then is training your body to only shift your eye focus once per phrase.
A NOTE FOR DIRECTORS
The above way of thinking of this principle with ones own eyes shifting once per phrase as being the way to show a new idea is helpful as a performer. But as a director, it is better to think of it as one change of the audience’s focus per phrase and have the shift happen at the end of the previous phrase. An actor shifting their focus can be enough to accomplish this but a change in lighting, scenery, movement of different characters or in the case of film change in shot viewpoint or style of a shot does the same thing. Directors have a wider range of tools to use to accomplish this principle of one eye-dea per phrase.