Traumatic subluxation causing variable position of the crystalline lens.

We present a case of traumatic lens subluxation that was evident only when the patient was in the supine position. This case illustrates that a crystalline lens with traumatic zonular rupture can change its position depending on the posture of the patient. If such a lens is suspended by the remaining zonules at the superior quadrant while the patient is erect, phacodonesis may be present while the lens remains in its normal position. However, when the patient is in the supine position, the lens drops back into the vitreous cavity. Examination in erect and supine positions is important in the preoperative assessment of patients with traumatic phacodonesis or iridodonesis.