This is a post by Mike Gayette on PTC site.
When you’re knee deep in a design, it’s easy to forget the big picture. You see: surfaces, materials, lattices, controls. Everyone else sees a wing mirror for their car.
Fortunately, you can switch back and forth between the orthographic and perspective views while modeling to help you keep some, well, perspective.
Using various perspective views settings, you can change the eye distance, focal length, and field depth for a realworld look at the design.
Think of Perspective View as a virtual tour of the design, from the end user’s point of view.