Representative resolution of various retinal imaging modalities relative to human retinal anatomy, inspired by Miller et al. (2011). Drawing of a sagittal section of a human eye created by Teresa Patitucci, PhD, Medical College of Wisconsin (not to scale). Histological cross section provided by Dr. Christine Curcio, University of Alabama at Birmingham, from a larger image originally published in Tian et al. (2015). The width and length of the shapes approximate the resolution of each modality (lateral and axial, respectively). None of these are absolute, as a number of variables can influence the actual resolution – including differences in imaging light source (wavelength, bandwidth), confocal pinhole diameter, pupil size, and axial length of the eye. Retinal layer labels: RNFL = retinal nerve fiber layer; GCL = ganglion cell layer; IPL = inner plexiform layer; INL = inner nuclear layer; OPL = outer plexiform layer; HFL = Henle fiber layer; ONL = outer nuclear layer; IS = photoreceptor inner segments; OS = photoreceptor outer segments; RPE = retinal pigment epithelium; ChC = choriocapillaris; Chor. = choroid. Scale bars = 50 μm.