On shaders with distorition, if you set opacity/angle different that the ones by default, this happens:
They have angle 1 and opacity 99.
When the sprite with a shader overlaps a side seems it manages the XY coordinates in a bad way.
The one with a light is a specular for a normalmap, the one in the right is the official lens2 shader by scirra.
Easy to replicate, just add a sprite, set white color and change angle or opacity, when you scroll and the sprite overlaps one side of the window does that.
Not only on runtime, it happens on C3 workspace too if you scroll.
Is a Bug Ashley ? If not, somebody know how to fix that?