The relentless need to define is more common in artists than I previously acknowledged. Searching for definitions of "visual theatre," I discovered a wide variety of companies who are more than willing to give an outline of the genre
http://visualtheater.co.il/pages/en/what_en.php



Visual theater is one of the terms in which a creative act - performed for an audience or with its participation - may be described as an act the language of which is first and foremost that of visual images. This language is not limited to the creation of a visual image. 

In its wider sense, it is a material, physical language that addresses all the senses and evokes mental images, a language in which every component - space, object, movement, voice or sound - may be equivalent to the actor and the human character. In contrast one may regard traditional theater based on the written drama, that is indeed presented visually but centralizes verbal discourse and its meanings.

In this wide space of action, visual theater defines itself as a form of expression that inherently rejects definitions, an area that subverts the delineating of areas. 

Perhaps this is why it is associated with such numerous definitions and modes of performance: 
performance art, installation, multimedia, puppetry, theater of objects, dance theater, theater of images, total theater, experimental theater and alternative theater. 

Visual theater sheds medium definitions or distinct genre headings in favor of interdiscipline, the combining and fusion of arts, skills and materials. Therefore a framework of studies geared to facilitate this must offer such a wide range of subjects: space design, sculpture, drawing and painting, directing, acting, puppet design and animation, street theater, bouffons, movement, dance and release techniques, music, voice training and singing,dramatic writing, lighting and video. At the same time, students touch directly upon interdisciplinary performance art, from focused etudes to the finalized work presented to the audience. In addition, this framework offers workshops facilitated by artists, active and known both in Israel and abroad. Experiential work is matched by theoreticalstudies linked to the practical aims of visual theater. Issues of performance art, the history and theory of stage design, art history, philosophy, film history etc.

In these and other dynamic and varied means visual theater defines itself as a goal to be pursued. 
Personal or collective exploration is to be aspired, seeking new and effective ways of expression and communication, and their spatial, physical, material, formal, musical, verbal or technological realization.
Visual theater is the goal to be pursued, and to no lesser extent, the actual daring to explore.

Defining the moment when visual theatre fully articulated itself as a genre is difficult: beyond Western theatre, Indian Kathakali or Japanese Noh are traditional forms that don’t fall easily into simple divisions of dance or drama, emphasising costume and gesture above the word, and mime, most famously codified into an easily recognisable costume by Marcel Marceau, became popular in the early nineteenth century.