You can gather from the following book chapter how relevant the analysis of tear fluid is for the personalised health risks assessment:

Golubnitschaja O., "What is the routine mitochondrial health check-up good for? A holistic approach in the framework of 3P medicine", in the book "PREDICTIVE, PREVENTIVE AND PERSONALISED MEDICINE: From Bench to Bedside", hardcover: ISBN 978-3-031-34883-9, eBook: ISBN 978-3-031-34884-6, in the book series "Advances in Predictive, Preventive and Personalised Medicine" - see here: springer.com/series/10051