What does a blue line around your body mean?

my mum who is only 40 has recently seen an electric blue colour about an inch away from her body,and after a week of only seeing it around her body she then noticed it around a cushion that she was sitting beside.also when she had these sightings she had a bad feeling about them and said she just felt extremly over-whelmed and felt full of nerves.does this mean anything? could this be spiritual or should she get her eyes checked out in case of it being a medical problem? please if you have any answers could you tell me please? thanks.