Vision is a major modality by which people obtain information and interpret the world, and investigating and improving vision is undoubtedly an important endeavor. Historically, papers on human vision were well represented in Optical Engineering. Over the last decade, however, the number of papers on this topic has declined. This special section on human vision is intended to bring vision, visual optics, and optics for vision back into the folds of the journal. This special section includes a series of articles that describe how optics is used to investigate human vision, how new methods for correcting or enhancing human vision are developed and evaluated, and how models of human vision can be used to design and evaluate other imaging systems. Several articles describe new optical imaging techniques such as quantitative anterior segment optical coherence tomography that measure 3-D biometry of the cornea and the lens in the front of the eye. Some of the techniques discussed here, such as aberrometry or reflectometric ocular optical quality analyzers, have already made their way into clinical practice and are being continually improved. Doppler measurements of physiological function may become standard diagnostic tools in the clinic. The better resolution, accuracy, and comprehensive information provided by these techniques will allow earlier diagnosis of disease, accurate monitoring of treatment, and guidance for treatment and surgery.