The Heavy Eye Phenomenon

Abstract

The association of a vertical deviation with anisometropia when the anisomyopic eye is hypotropic is termed the heavy eye phenomenon. We reviewed patients with anisometropia of greater than 2D to see if a vertical deviation was present and what could be the cause of the vertical deviation. Of 95 patients reviewed only 7% had a vertical deviation in primary position. We could not relate the size of the horizontal deviation, the amount of anisometropia or oblique dysfunction to be the cause of the vertical deviation. Since the association of a vertical deviation with anisometropia is rare, it may not be due to anisometropia but to the dissociation by the anisometropic amblyopia.

• heavy eye
• anisometropia
• vertical deviation