Abstract: Since its introduction, optical coherence tomography (OCT) has been dramatically improved. The first developments of OCT involved time-domain OCT, wherein the image was acquired point-by-point by scanning both the interferometer reference arm length and the laser beam [22,26,37,62]. Frequency-domain (Fourier-domain) OCT soon followed, where the reference arm length scan was replaced by spectroscopic measurements made in parallel using a spectrometer (spectral-domain OCT), or sequentially by scanning the wavelength of a tunable laser (swept-source OCT) [23,33,46,50,66,67,70,72]. Since the depth information in frequency-domain OCT is obtained more rapidly, a significant improvement in the image acquisition speed and/or signal-to-noise ratio was achieved [7,10,45]. The success of OCT in many biomedical applications, especially in ophthalmology, suggests that it may seem futile to revisit the technique. This chapter explains the principle of the full-field OCT technique and its associated operational performances. The primary advantages and drawbacks of the full-field OCT technique, compared to conventional OCT, are discussed.