An auto darkening eye protection device including a shutter assembly, a control circuit, and a power supply. The control circuit includes a sensing circuit for sensing the occurrence of welding, and a delivery circuit to provide signals to the shutter assembly to cause the shutter assembly to transition to the dark state. The power supply supplying power to the control circuit and the delivery circuit. The power supply including a power regulation circuit, and a solar power supply supplying electrical power to the power regulation circuit and the sensing circuit. The power regulation circuit limiting the voltage of the solar power supply to a predetermined voltage to provide a stable reference voltage.