Hi @todokoro, thanks for you interesting suggestion.. I assuming you are referring to implementing a camera switching within an eye controlled game? Generally this kind of functionality is down the game’s manufacturers themselves to implement so I would definitely suggest you post this cool feature request on their own forum also!
In the meantime, you may be able to setup a customised solution using a 3rd party application such as project IRIS which may permit custom macros.
In terms of doing this programmatically, did you have in mind which API to use? The most relevant choices for you would seem to either be the Core SDK for Interaction purposes or the Unity SDK for custom in game interaction.