A system includes a resonant circuit having an inductor coupled to a piezoelectric oscillator. The system also includes one or more light emitting diodes (LEDs) configured to generate illumination based on an output of the resonant circuit. The system further includes a frequency generator configured to frequency modulate the output of the resonant circuit. In addition, the system includes a power supply configured to provide a voltage to the resonant circuit and activate a piezoelectric effect in the piezoelectric oscillator. The piezoelectric oscillator may include a piezoelectric material that is configured to undergo electrical distortion in response to an applied voltage from the power supply. The frequency generator can be configured to alter a capacitance and/or an inductance of the resonant circuit. The illumination can be applied to the retina or other tissue of a body to adjust a pH of cells in the tissue.
