The Perspective filter can be used to either correct converging perspective lines caused by lens distortion, or to apply perspective for a creative effect.
Lens distortion can often cause the perspective of a photo to be out, creating the appearance that lines are not vertical or horizontal when they should be.
The Perspective filter can be adjusted in single or dual plane mode, if applied via the Filters menu (Distort category). If using the non-destructive, live filter, only single plane mode is available.
The live filter can be accessed via the Layer menu, from the New Live Filter Layer category.
The following settings can be adjusted in the filter dialog: