If you're looking for some simple distortion transitions in Premiere Pro, Justin Odisho has you covered. He creates this fisheye / pincushion transition by applying and animating the Lens Distortion effect on an adjustment layer centered above the edit point between two clips. This is a cool looking transition that can add a lot of style to your edits. And it's very easy to do.

In this Adobe Premiere Pro CC 2017 Tutorial, I will demonstrate how to create a fisheye or pincushion distortion transition effect using lens distortion effects and adjustment layers. —Justin Odisho

Source: https://youtu.be/t4q901M4LIg