Darling. Lex and Mary Duncan. Personal work from the ongoing photo essay "Darling." Lex Duncan has been caring for wife Mary Duncan at home since she was diagnosed with dementia in 2008. Currently, about 750,000 Canadians are living with cognitive impairment, including dementia, but that number is expected to double by 2031, according to the Alzheimer Society of Canada. The care will often times fall on the family members - the husband, the wife, the son, the daughter or even the grandchildren. Lex Duncan, wouldn't have it any other way and neither would Mary Duncan. He believes he can give her the best care at home, however it's not easy. "You think you'll live forever and never have any problems," says Lex Duncan, "But life ain't quite like that."