Thermal-controlled cholesteric liquid crystal wavelength filter lens for photosensitive epilepsy treatment

Cholesteric liquid crystals (CLCs) exhibit optical properties that are highly responsive to temperature or electric fields. Here, we report an approach to aiding in photosensitive epilepsy treatment by developing a thermal-controlled CLC wavelength filter lens. This lens demonstrates exceptional optical tunability, enabling it to dynamically change its stopband in response to temperature changes. At room temperature, the stopband of the CLC lens is outside the visible spectrum, rendering the lens functionally similar to normal glass. As the temperature rises to 36.5°C, the lens efficiently blocks light within the 660- to 720-nm wavelength range, which is the known trigger wavelength for photosensitive epilepsy. CLC materials with opposite handedness are used to achieve over 98% light cutoff at the stopband. We propose a control system for dynamically controlling the temperature in real time. The tunable lenses offer a solution for mitigating the effects of specific light stimuli on affected individuals.