Single molecule (SM) fluorescence microscopy provides non-invasive means to localize biomolecules and characterize their diffusion in cells with a sub-resolution precision. Extending SM imaging techniques to live animals is an exciting, yet challenging endeavor that can potentially reveal how pathological processes affect the nanoscale mobility and the function of biomolecules in their native three-dimensional tissue environment. Here we used Complementation Activated Light Microscopy (CALM) to target, image and track individual voltage-dependent Ca2+ channels (VDCC) with a precision of 30 nm on muscle cells and within neuromuscular synapses of normal and dystrophin-mutant Caenorhabditis elegans worm models of Duchenne muscular dystrophy. Through diffusion and spatial pattern analyses, we show that dystrophin is a load-bearing apparatus and a tension transducer that modulates the confinement of VDCC within sarcolemmal membrane nanodomains in response to varying muscle tonus. SM imaging by CALM opens new avenues to explore the basic principles of homeostatic controls and the molecular basis of diseases at the nanometer scale in intact living animals.