My mother suffered from this. When I’d go into her room at her facility, she would have the shade pulled down tight. She was very paranoid and I think she did that because she was afraid of someone looking into her room. But, I’ve always felt this contributed to her confusion. I tried to make sure to pull up her shade or convince her to go to the lounge with me so she could see it was sunny and bright out. I even got her a talking clock that would say “AM” or “PM”. But, after a while the confusion was just too overwhelming for her. She got to the point she really had no concept of time or days.
Can you please provide a little more info: How old is your wife? Has she been diagnosed with dementia or ALZ or something else? Is this a new issue? What are her behaviors related to this problem?