The all vision visor is an extendable retractable polarized sun visor that utilizing a prism and light source that is rotative relative to a housing slot whereby the user can vary the color wavelength projected into the sun visor that refracts incoming sun rays, while allowing full vision through the windshield from the interior of the automobile.
Assume that the position of a sun visor main body is adjusted by an occupant when incident light having the incident angle .theta.1 has entered a vehicle passenger compartment. Then, a straight line L1 is obtained that passes through the distal end position S1 of the moved sun visor main body and is inclined by the same angle as the incident angle .theta.1. At this time, the intersection between a straight line Y1, which passes through an eye position P0 of a average sized person and extends along the vertical direction of a vehicle, and the straight line L1 is estimated as an eye position P1 of the occupant. Thereafter, a light blocking control is performed in accordance with the estimated eye position P1.
