Fig. 3. Three common retina in vivo optical imaging methods distinguished by the input and output optical path on the pupil. (a) Possible input and output light path locations related to the pupil; (b) fundus camera; (c) scanning laser ophthalmoscope; (d) optical coherence tomography

Fig. 4. Representative mouse retina pictures obtained by three common optical imaging methods. (a)--(d) Fundus photography, fluorescein angiography, large-field (50°) fluorescence labeled ganglion cells, and digital zoom-in ganglion cell image, respectively^[23]; (e)--(g) back-reflection, fluorescein angiography, and zoom-in scan of fluorescein angiography, respectively^[23]; (h) ganglion cell image from SL

Fig. 5. Effect of visual aberration on imaging, and two adaptive optics aberration correction methods. (a) Effect of used pupil size on imaging. For simplicity, only the output beam through scattering of retina is considered. When the beam occupies small percentage of the pupil, the aberration has a little effect on the PSF_A. When larger pupil is used, more aberration will be introduced, resulting in blurred imaging; (b) adaptive optics system based on Shack-Hartmann wavefront sensor (SHWS) f

Fig. 6. Represented AO-SLO images of the mouse retina. (a)(b) Images of photoreceptors under two different amplifications^[19,30]; (c)--(e) slicing diagram using the back-refection light imaging: different structures in the same lateral location but with different depths^[19]; (f)--(h) slicing diagram of fluorescence imaging: the same ganglion cell with different imagi

Fig. 7. AO-SLO blood vessel imaging, blood flow measurement, and two new imaging techniques. (a) Two scanning patterns for imaging (single arrow) and blood flow measurement (double-headed arrow) based on AO-SLO^[31]; (b) blood vessel imaging^[31]; (c) space-time image of blood flow signal when the longitudinal scanning position is fixed at one point of blood vessel image. The blood flow speed can be calcula

Fig. 8. Mouse retina optical multimodal imaging based on WFSL-AO. Along with the searching process, (a) the image brightness is increasing, (b) the wavefront aberration is decreasing, and (c) the images before and after optimization are compared^[97]; (d) back reflection (red represents blood vessels and nerve fiber bundles) and fluorescence (green represents ganglion cell) composited SLO images, (e) fluorescence-labeled microglia cells, and (f) angiograp

Fig. 9. Oblique laser scanning ophthalmoscopy^[110-111]. (a) Imaging principle: the incoming light comes into one side of the pupil, and the scattering light comes out from the other side of the pupil. This oblique input makes the detector can detect depth information; (b) depth encoded 3D fluorescent angiography from a mouse retina; (c)(d) two cross-sectional images are exemplified along the vertical and horizonta

Fig. 10. Visible light high-resolution structural imaging and retinal oximetry. Comparison between (a) NIR-OCT and (b) VIS-OCT with achromatization for imaging of macular area in the same eye [lateral and axial resolutions of Fig. 10(a) are 10 μm and 1.7 μm respectively, and lateral and axial resolutions of Fig. 10(b) are 15 μm and 4 μm respectively)^[95]; (c) averaged VIS-OCT enab

Fig. 11. Two different ways for suppressing the speckle noise in the living retina imaging. Passive: (a) acquiring the 3D data multi times in the same location and averaging after alignment; (b)--(d) the image changes in GCL with averaging times^[145], and (e) its quantification result^[145]; (f)(g) comparison between single and averaged OCTA images of the OPL layer for a mouse retina^{[Download full size}

Fig. 12. Studies of the retina function response to visible light stimulus. (a)(b) nm-level human retina responses to two different light stimulus patterns and (c) the corresponding precision measured result^[165]; (d)--(g) intrinsic optical signal (IOS) measurement^[168]: (d) differential image of IOS with 10-ms light stimulation at different time; (e) IOS curves for different retinal layers; (f) enlarged

Table 1. Comparison of several key parameters of mouse and human eyes^[19-20]