Malposition of the head usually has a cause, and the patient may be unconscious in adopting an abnormal head position. Therefore, it is important to be aware of any abnormal head position: 1. Tilting the head or turning the face to improve vision. The most common cause of tilting the head or turning the face is nystagmus, and the patient may adopt a head position in order to improve vision so that both eyes are located in the central band of nystagmus, obtaining the maximum amount of time of center-concave gaze. 2. Refractive error. Oblique-axis astigmatism can cause an abnormal head or face position that disappears once the refractive error is corrected. 3. Ptosis. Children with severe unilateral or bilateral ptosis may adopt a chin-up position and look through the underside of the upper lid to maintain fusion; if the child has been doing this before and now stops, be alert for amblyopia or loss of fusion. 4. Strabismus. As an example, a patient with right upper trapezius paralysis adopts a left-tilted head position in which the eyes are orthoptic and fusion is obtained, and when the head position is shifted to the right shoulder, there is vertical strabismus with diplopia present. If the strabismus exceeds 10 degrees in the abnormal head position, this head position is not taken to obtain fusion.