What is possibly the most helpful advice a doctor has given you?

For me it happened when I saw my doctor during Covid and told him about my leaking eyes. The tears were being a nuisance running down my cheeks under my mask.
His advice was to use cotton pads soaked in a solution of Johnson’s Baby Shampoo and applied to the eyes twice daily.
Result - my eyes stopped being an issue thus avoiding a possible operation.
I still cleanse my eyes morning and night so as not to have a repeat of the problem.
Have you got a tip a doctor has given you worth sharing?