[The 'Veenhuizen ophthalmia']. 
In 1860 the institutions of the former Society of Welfare in Veenhuizen, the Netherlands, which had been taken over by the state, were struck by a mysterious eye disease.  More than 5000 orphans and former beggars lived and worked in these institutions.  The Minister of the Interior ordered an inquiry by the ophthalmologist Herman Snellen (1834-1908).  He reported that the inmates slept in close proximity to one another and had to share dishes and towels.  There was no clean water for washing or drinking.  788 (15%) people were found to be suffering from trachoma.  On Snellen's advice, a start on improving the standards of hygiene was made but no more was done.  The real reduction in prevalence came around 1900 and was probably connected with a reduction of the number of inmates and improvements in hygiene.