Timothy C. Hain, MD • Page last modified: August 27, 2022

A vertical heterophoria is a vertical misalignment of the eyes.  A vertical phoria means that the eyes are aligned with both eyes viewing, but when one eye is covered, the covered eye drifts up or down. A phoria is not the same thing as a tropia. A tropia means that the eyes are looking in different directions, with eyes open as well.

The presence of a vertical phoria has been found to be associated with symptoms of motion sickness.   Vertical phorias may also cause symptoms of double vision, head tilt, and eyestrain.    A recent study found that correcting for the vertical heterophoria with spectacle prisms reduced symptoms of motion sickness in 50% of patients. (Jackson and Bedell, 2012)

Vertical phoria is also associated with concussion and a variety of other illnesses.

Literature summary:


Very little has been written about vertical heterophoria. There are several recent papers suggesting that vertical heterophoria can be acquired from TBI, and that treatment with prisms is helpful. More study of this is needed. Chicago dizziness and hearing has a visual vertigo specialist and we can evaluate for this condition.

Vertical phoria adaptation is fast (time constant of about 30 minutes). One would think that this response should not be due to durable changes in neural "wiring".