Microvascular Cranial Nerve Palsy (MCNP) is when there is a blockage in blood flow to nerves in your head. As a result, muscles that move your eyes do not work properly. You have trouble moving your eyes a certain way, and you have double vision. Sometimes you have blurry vision or a droopy eyelid. MCNP is more likely to happen to people with high blood pressure and diabetes.

MCNP usually goes away on its own in about 6–12 weeks. Patching one of your eyes or wearing prism glasses can help with double vision while you recover. Sometimes, if the eye muscles do not recover completely on their own, muscle surgery is recommended.

To prevent MCNP, you need to control high blood pressure and blood sugar levels, and quit smoking.