A light controlling device having excellent controllability of light and solar energy transmission which comprises a suspension of anisotropic particles in a liquid dielectric medium and a pair of electrodes for applying an electric field to said suspension, and said anisotropic particles having an aspect ratio of at least 3.5 and comprising an inorganic titanium compound having an absorption coefficient of at least 5 x 10³ cm⁻¹, especially a titanium compound of the formula: TiOxNy wherein 1.37 ≦ x+y ≦ 1.95 and 0.15 ≦ y ≦ 0.92.