Inclusion Criteria:  age 65 years or older diagnosis of dementia a score ≥ 4 points on the Global Deterioration Scale (GDS; Reisberg et al., 1982), ranging from moderate to very severe cognitive decline.  Exclusion Criteria:  high ocular sensitivity to light (photosensitivity) preexisting ocular abnormalities having any severe ocular disorder that did not allow them to open their eyes or that implied a very low visual acuity.