“Cheng” means to take or to receive. “Guang” means bright. The point is located on the top of the head, where the light of the heaven first strikes the body. The point is also effective in the treatment of eye conditions, promoting the eyesight and thereby letting in the brightness of the outside. Hence the name Chengguang (Taking Light).
On the same line as Tongtian (BL7) and Luoque (BL8), 1.5 cun lateral to the anterior posterior midline of the head, the distance between adjacent points being 1.5 cun. The tips of the thumb, index and middle fingers may be used to form an equilateral triangle with a distance of 1.5 cun between each of the tips. Place one of the three fingers on Baihui (GV20), so that the finger to the front touches the point Tongtian (BL7) and the finger to the back touches Luoque (BL8). A similar method can be used to locate Wuchu (BL5) and Chengguang (BL6), is by placing one of the three fingers on Xinhui (GV22).
Blurring of vision.