A new optical modality to overcome diplopia.

The author has presented a new method to correct vertical diplopia using a prism contact lens. To the present time, its application has been limited to contact lenses correcting refractive errors of less than 3D and to ground-in prisms of not more than 6 delta. The field is new. Technical, mathematical, and clinical advances should eventually allow the use of stronger prisms over a wider range of refractive corrections.