Just an observation - I looked after a young man once who had been mysteriously paralysed, and gone blind. A series of hospitals and specialists couldn't diagnose why this brilliant young man in his early twenties (he'd been working on his PhD when it happened, but had gone travelling round the world the year before) was now in a wheelchair and in constant pain, incapacitated. At length his parents decided to give him a measure of independence by buying a bungalow for him where he could live on his own, with carers coming in (yes, his family were pretty wealthy but no amount of private doctors had been able to help.) Mysteriously, he hadn't been in the bungalow long before he began to improve, and before the year was out he was back to full health, sight restored, driving a car and working. It eventually turned out that the cause of all his problems was an intolerance to some substance(s) in the dishwasher tablets that his parents used. Once in the bungalow, his carers just washed up by hand using Fairy Liquid and rinsing. His parents had got the dishwasher during the years he was away at university, degree, postgrad, and then travelling; but when doing his PhD he moved back home. Makes you think!