There is a related situation in bearings only tracking known as the observably condition. For a single sensor, observing a single object, in general terms, the observer must be able to maneuver more than the object.
A fully rigorous treatment involves Lie algebras, of which a Google Scholar search will produce many references, most more advanced than my background.
The advantage of two eyes are obvious in the context of natural selection. Avoiding movement is stealthy. Two eyes would estimate range much faster.