Confusion just seems to increase

Mother's confusion just seems to increase. We know it's to be expected, but it's still hard to see. Most days she cannot find her room at all, even if she just came out of it. She also doesn't believe it IS hers when we lead her to it. An interesting new twist has been that she can't seem to see that there is a room there at all, unless the light is on in it. Even a couple of weeks ago, she would just flip the switch on as she entered the room. Now, she seems to believe that it is "outside" in there, because it is dark. We are trying to always keep the overhead light on in her room at all times. Hopefully that will help.