Over the last few months I have found my 90yo Mom who has dementia doing a lot of things in the dark. She doesn't turn lights on. For example: she won't turn the bathroom light on when she's brushing her teeth or washing up before bed. Last night she was up (confused) at 1AM getting dressed for the day and sorting her clothes in her dresser, all in a totally dark bedroom. When I tell her we can turn the light on she says "I can see ok." She does have a history of age related vision problems but they are stable and she reads a lot (though comprehension is very limited) and if she sees me reading in light that she doesn't think is adequate she always reminds me to turn a light on. She does have a small night light in her bathroom that is left on.
Have any of you seen this behavior in demented persons? It's not a big issue but it is weird.