In conclusion, we have quantified the number of sp 3 quantum defects in (6,5)-SWCNTs using fluorescence imaging and spectroscopy. We established a linear relationship between the different optical features and the sp 3 defect number. Most importantly, we found that quantum defects in SWCNTs follow a Poisson function with very low numbers (n=0-3). Moreover, we could follow and also count the incorporation of quantum defects live in the microscope on the single nanoparticle and single molecule level. This work provides deep insights into how tiny perturbations (single quantum defects) at the level of individual units in a carbon lattice fundamentally alter the optoelectronic properties. It paves the way for precise tuning and understanding of material properties using quantum defects and color centers. Such developments are the basis for advances in photonics such as single photon quantum protocols as well as imaging and (bio)sensing.