Means of direct visualization through a curved approach path

A coupled pair of retractors which are coupled at the distal end to allow the handles at the proximal end to be urged apart to increase the distance between handles to allow for direct line of sight to the surgical site while also allowing the use of curved tools and curved access to the surgical site. A cannula with a cross section taken perpendicular to a straight portion of the cannula that increases between the proximal end of the cannula and the distal end of the cannula allows for direct line of sight to the surgical site while also allowing the use of curved tools and curved access to the surgical site. These tools may be used in a postero-lateral approach from an incision in the back to a target position adjacent to the spine.