Xiyan xī yǎn · 膝眼

Location. With the knee flexed, in the depressions on both sides of the patellar ligament. The medial point is called Neixiyan; the lateral one is the same location as Dubi (ST35). Two points on each knee, four in all.

The name describes the two dimples that appear beside the kneecap when the knee is bent, like a pair of eyes. Recorded as a pair in the classical literature on the knee.