My sorrow to you also, Griff.
My Mum is suffering from Grandad's physical decline.
He has recently decided he has a horror of going into a home, and has started saying he doesn't need to - he can get by on his own. What he means is he can cope if he has more and more input from Mum. She's looked after hom for years, but now he needs a visit at least twice a day (not including the carers who come morning and evening) as well as all the gardening, cleaning, laundry and ironing she does for him.
I'm sure mental decline is more horrifying, but seeing a parent's mood decline and them become fractious and ungrateful because of their physical disabilities (cataracts and Parkinsons in Grandad's case) is also painful.
Thank goodness for decent and loving children.
I think I'll just have to take the overdose way out when I get that age