Described herein are apparatus and associated methods for the generation of at least one user adjustable, accurate, real-time, virtual surgical reference indicium including natural patient vertical for use in ocular surgery. The apparatus used to generate real-time, virtual surgical reference indicium including natural patient vertical includes one or more real-time, multidimensional visualization modules, one or more data processors configured to produce real-time, virtual surgical reference indicia, and at least one user control input for adjusting the at least one real-time virtual surgical reference indicium including natural patient vertical. The associated methods generally involve the steps of providing one or more real-time multidimensional visualizations of a target surgical field, identifying at least one visual feature in a pre-operative dataset, aligning the visual features with the multidimensional visualization, and incorporating one or more real-time, virtual surgical reference indicium including natural patient vertical into the real-time visualization.
