Different things can cause photophobia. Is she taking vitamins? Sometimes certain vitamin deficiencies can cause this. I am not a dialysis nurse and not very familiar with signs and symptoms related to kidney problems. Talk with her PCP if this problem continues. Even the dialysis nurses would probably have good information for you. Sometimes nurses are more in touch with patients than the doctors due to the amount of time spent with patients. :) Of course, I am a little partial!!!!
This symptom (sunlight sensitivity) is the hallmark of a bleed within the brain. This is the most likely etiology.
As usual, physician ignore the problems of the elderly.
Your mother requires an MRA (not an MRI) as of yesterday.
And a new physician.