Why does my Alzheimer's wife keep her eyes closed all the time?

My Mom used to do this. When she did she actually made sense. Maybe its a way to get away from the confusion and being overwhelmed. Like a child, if they shut their eyes, ur not there.

There is always the possibility she is having problems with her eyes, her glasses may no longer be right for her or she has sore or dry eyes.
I've seen this often though and I think it is a way to decrease confusing stimuli, I have read that in some forms of dementia there are changes to the visual part of the brain and images are confusing or distorted.
I also think that in later stages it is part of the gradual withdrawing into oneself that is a precursor to end of life.

Rosered6 below mentions the same thing. I will be so interested to see if others have this as well. I do know that they at times try to disengage from a confusing world, esp if they are suffering any delusional states. Also there is the very late stages where honestly it is a bit of the age old "turning one's face to the wall" and disengaging from life. Other than that, I wonder if in some cases it is entirely unrelated to their dementia, but something other. I have one eye that is not good after a vitreous separation. I have to close it at times, esp if reading, so my brain doesn't try to unscramble the two different outputs from my eyes being so different. I also get a lot of dry eye, a lot of allergy, and find myself closing my eyes because of that, or a bit of a burn, just to rest them.
Fascinating question. I will be so interested to hear what others have to say.

I don't know but I will be interested in any answers. I saw my ex-husband's mom yesterday for the first time in a long time. She is in a late stage of Alzheimer's disease. Her eyes were closed the entire time she was here but she clearly was awake.