Head-Cancelled Virtual Reality for Ocular Cranial Nerve Palsies

OCNP Group Inclusion Criteria:

* Presence of OCNP in one eye with 50% range-of-motion limitation or worse
* Able to provide informed consent and will be able to fluently read and understand spoken English

OCNP Group Exclusion Criteria:

* Presence of bilateral OCNP
* Range of motion better than 50%
* Visual acuity worse than 20/100 in either eye
* Greater than 4-line difference in visual acuity between the eyes,
* Structural anomalies or sensory sensitivities (e.g. visual motion sensitivity) that would prevent them from wearing or tolerating a VR headset

Participants will be excluded if they are unable to participate if inclusion criteria are not met.

Normal Group Inclusion Criteria:

* Absence of OCNP or other neurological or neuro-ophthalmic diseases
* No strabismus
* Have normal or near-normal vision with glasses or contact lenses.
* Be able to provide informed consent and will be able to fluently read and understand spoken English

Normal Group Exclusion Criteria:

* Visual acuity worse than 20/100 in either eye
* Greater than 4-line difference in visual acuity between the eyes
* Structural anomalies or sensory sensitivities (e.g. visual motion sensitivity) that would prevent them from wearing or tolerating a VR headset
* Known inability to tolerate visual testing of at least 20 minutes continuously.