I Optical Effect: curved light source when seen through the bus window

[Marth]

During the night, I was traveling by local bus. And as I viewed through the window, the light from the street lights and the headlights of other vehicles appeared curved, as shown in the images below:

One common answer is: because of refraction
Is there any more explanation for this behavior?

 

[berkeman]

Welcome to PF.

Is there any more explanation for this behavior?

The window is curved...

 

[Marth]

No, it is not. That's a perfectly flat glass surface.

 

[DaveC426913]

Pretty sure those are reflections off streaks on the glass - could be oil, could be residue from a cleaner.

These, but curved:

 

[DaveC426913]

Upon further "reflection" I am not convinced this is an effect of the glass.
It's got to be an artifact of your camera.

The streaks are perfectly circular, perfectly concentric, and their origin is in the direction your camera is pointed.

Is it an uncropped image? I don't suppose you cropped off the left side of the image did you?

 

[DaveC426913]

In fact, there seem to be two foci of concentricity in discrete areas:

They could very well be fingerprint smudges on your lens.