If it were a mechanical system, perhaps. But biology suggests that visual experiences will shape the way neurons connect during the brain's development...I hate computer analogies but consider all previous visual experiences as the training corpus for the brain's neural network. The response to a particular stimulus from one eye could readily evoke a response to that triggered by two eyes. The evidence is that people can usually read with one eye closed, under variable lighting conditions, partially obscured text, and wrds mssng vwls...though sometimes #/w is considered a vowel.