Positive canthal tilt

Positive canthal tilt describes an eye whose outer corner sits higher than its inner corner, giving a slight upward slant. It is the typical adult configuration rather than an unusual one: the oculoplastic literature places the usual range at roughly two to eight degrees positive, with variation by ancestry and a small difference between a person's own two eyes being normal. Because it is the common case, a positive reading is not evidence of anything in particular, and a reading well above eight degrees is more often a low camera angle than a remarkable eye. The angle is determined by where the lateral canthal tendon anchors to the orbital rim, so it is fixed in adults; the appearance can be affected by brow position and under-eye volume without the underlying angle moving at all.