A number of additional embodiments and optical constructions of a relaxed confocal catadioptric scanning laser opthalmoscope (SLO) are disclosed. They improve the functionality of microperimetry (MP), and the integration of the existing instrument with the capabilities of high speed spectral domain optical coherence tomography (SD-OCT). The improvements pertain to enhanced acousto-optic modulation with regard to rise-time and combination of wavelengths, enhanced control of illuminating beam characteristics and separation of illuminating and returned light within the SLO, enhanced electronic control and options for the galvanometer--polygon combination, additional use of a liquid crystal spatial light modulation, and the modalities under which SD-OCT can be integrated within the SLO.