tic nerve head, which all lie beneath the highly remittive retina; [0027] macular edema, which may contain proteins, lipids, or other compounds as well as fluid that thickens and elevates the retina; [0028] the birefringent cornea, or the retinal ganglion cell axons found in highly polarized nerve fiber bundles, which themselves are understood to have a strong axis of polarization; [0029] choroida