Abstract: A Venetian blind including a head rail, a tilting device, two or more tilt cords, a bottom rail, a predetermined number of draw cords, a cord pulley retainer, and a plurality of slats fastened to the tilt cords such that the slats are spaced equidistantly and parallel to one another and that the slats can be adjusted at any angle to regulate the light by the tilting device. Each of the slats is provided with two or more through holes located on the same side of a center line of the slat. The through holes of one slat are therefore obscured by the lower edge of another slat located thereover at the time when the slats are in an upright position to keep out the light.