This is little confusing. Who said she has macular degeneration?
My Mother did have it ... and she does have dementia at a fairly developed stage. There can be many things imagined by someone with dementia, but have you seen a doctor for diagnosis of that?
I've watched people with serious dementia (where my Mother is at) and their reactions can vary tremendously. Some I've seen seem to be happy all of the time. Others are very distant. And yet some others are very crabby most of the time.
I doctor is the best place to start. Don't let the word Psychiatrist scare you. That might be the best place after you see your primary doctor. You do need a professional trained opinion ... and maybe some tests.
As long as there's no violence by your mum ..... everything should be very workable with a solution.
Best wishes ............................................ Rob