We study the optical properties of the Kehagias–Sfetsos (KS) compact objects, characterized by the “Hořava” parameter omega_(KS), in the presence of plasma, considering its homogeneous or power-law density distribution. The strong effects of both “Hořava” parameter omega_(KS) and plasma on the shadow cast by the KS compact objects are demonstrated. Using the weak field approximation, we investigate the gravitational lensing effect. Strong dependence of the deflection angle of the light on both the “Hořava” and plasma parameter is explicitly shown. The magnification of image source due to the weak gravitational lensing is given for both the homogeneous and inhomogeneous plasma.