I Am A Concerned Grandmother, My Question Is My 5

I am a concerned Grandmother, My question is my 5 yr old grandson has reoccurring pink eye to often. I know from experience that cleanliness in an environment help to prevent cases as such. I was a preschool teacher and this was stressed to parents. Wash, wash, and wash hands and do not touch your face was told to children and information give to parent especially during the winter season. What is your honest and professional word wisdom on this. Concerned Grandmother