You can configure the detail levels for various objects here.
Higher values lead to a finer wireframe and therefore to a better approximation for the displayed objects, but slow down rendering. For some objects like the sphere you can configure the detail level for two directions separately.
If you check the High detail for enhanced projections check box, all wire frame lines are subdivided further if the camera uses an enhanced projection. Enhanced projections are all projections except the perspective and orthographic projections. This feature greatly improves the approximation of these projections but slows down rendering.