Optical coherence tomography (OCT) is a new imaging modality that provides cross-sectional tomographs of ocular structure in vivo. OCT system utilizes propagation of light through, and the time-of-flight delay of light reflected back from biological tissue to produce false-color images of microstructure. OCT has superior spatial resolution (10 microns) than other optical imaging instruments, and maybe achieved at arbitrary penetration depth in transparent tissue with a noncontact, noninvasive measurement. Such features make OCT useful for the early diagnosis, differential diagnosis and more sensitive monitoring of a variety of ocular abnormalities including glaucoma, retinal and anterior eye diseases.