I think my paperwhite has the same issue as yours, with light on the left hand side.
It is really distracting but the amazon person I spoke to on the chat (I showed them my image of the problem), said this was "normal" and that she had checked her kindle and the light was the same on hers. So they won't replace it.
See my issue here:
Does that look the same as yours did, and also how easy was it to get them to agree to a replacement because it doesn't seem right to me!
Was the replacement better?