Figure 7. 2-photon excitation fluorescence (2PEF) and second harmonic generation (SHG) of TM region of a human eye from an 88-year-old donor. A section of a human eye was labeled with the cell-permeable nuclear stain (Hoechst 33342) then flat-mounted with the anterior chamber facing the microscope objective. A 2PEF emission window for Hoechst (473 nm to 505 nm) and a SHG emission window (388 nm to 409 nm) was collected from an 800 nm excitation. Multiple tiled scan were performed at the aqueous humor surface of the TM (0 µm) and at −5 and −10 microns below the surface. White=SHG signal, blue=Hoechst. White scale bar=100 µm.