Multiple commercial femtosecond lasers have been cleared for use by the US Food and Drug Administration for ophthalmic surgery, including the creation of corneal flaps in LASIK surgery. Optical coherence tomography (OCT) is an established medical imaging technique that uses light to capture micrometer-resolution, three-dimensional images from within optical scattering media (e.g., biological tissue). The combination of femtosecond laser surgery and OCT imaging is useful to provide simultaneous guide to the development of next-generation femtosecond surgical lasers in cataract surgery and to explore novel femtosecond-laser surgical strategies. This Spotlight explains the principles of OCT-guided femtosecond-laser cataract surgery.