Recent examples of our work along three major lines of research will be presented in this seminar. In the front of quantum biology I will talk about a new measure of quantum coherence relevant to radical-pair reactions and based on quantum relative entropy. Regarding our work on quantum sensing I will describe a recent experiment on spin noise in coupled dual-species alkali vapors, and theoretical work on the quantum foundations of spin-exchange collisions. Finally, regarding our new research direction on quantum vision I will talk about a recent measurement of the pupil light reflex using a novel laser light source, and discuss upcoming experiments aimed at studying vision by use of quantum light sources.