Brightness around edge of field of view

[Jove]

Last night I really noticed that view through most of my eyepieces (half decent Plossls I'm lead to believe) is only really dark in the middle - there's a glow around the edges. It's worse on the higher power eyepieces (in fact on the 40mm the whole field is pretty dark). Is this just one of those things to get used to or is it a product of there being a lot of light pollution, or perhaps stray light reflecting of the eyepiece (and so might be helped by some kind of hood?).

It's not really a problem, I just only really noticed it last night while trying to tease out M53.

Thanks!