[ Refresh ] redraws the model on the screen. It also deselects the selected items.
[ Select ] sets the Operation Mode to SELECT. Coordinates at the mouse are shown only in SELECT mode.
[ Translate ] sets the Operation Mode to TRANSLATE.
[ Rotate ] sets the Operation Mode to ROTATE.
[ Zoom In/Out ] sets the Operation Mode to Zoom: In/Out.
[ Zoom All ] resets any translation, rotation, and zooming.
[ Move to Center ] sets the Operation Mode to Move to Center.
[ Zoom In/Center ] sets the Operation Mode to Zoom In/Center. The operation combines Zoom In and Move to Center.
[ Zoom Out/Center ] sets the Operation Mode to Zoom Out/Center.  The operation combines Zoom Out and Move to Center.
[ Zoom 50% ] to [ Zoom 1000% ] sets the viewing size of the model.
[ Actual/Fit View ] switches the View Mode.
[ Clipping ]  sets the visible portion of the model.  Only the model within the specified X and Y range is visible on the screen.

[ Show/Hide toolbar ] shows or hides the tool bar.
[ View Option ] sets the options for the view.

Also see View Option Details