Abstract: An automatic liquid-crystal light shutter includes a NAND gate integrated circuit and a pair of RC oscillators operating in cooperation with two solar cells which experience internal resistance changes in response to received light. The changes in the internal resistance of the two solar cells results in a comparison signal which is applied to each of two NAND gates along with respective oppositely faced oscillator signals. When the NAND gate output signals are of different potential, the shutter passes light with little or no attenuation. If the NAND gate output signals are of the same potential, the liquid-crystal shutter becomes highly attentuated or unpassable for light. As a result, the automatic liquid-crystal shutter automatically passes low intensity light but attenuates or blocks high intensity light.