Radiographic Head and Neck Positional Changes in Response to Usage of Low-powered Prismatic Lenses

Inclusion Criteria: Presentation of diagnostic criteria for Postural Deficiency Syndrome comprising of * Two or more cardinal signs of Postural Deficiency Syndrome * Clinical presentation of asymmetrical stance and head extension and rotation * Presence of typical directional pseudoscotoma described in this syndrome Exclusion Criteria: * Vision under 8/10, strabismus or nistagmus; * Previous eye or vestibular surgery; * Known disease affecting the central nervous system or inner ear; * Medication with known interference with balance and posture and * treatment for postural and movement disorders in the previous year.