Occasionally MCNP may result from a blocked vessel in the covering of the brain, which can be associated with pain around the eye. The nerves are not permanently injured, and over a period of six to 12 weeks, a good portion of normal function should recover. If double vision from MCNP does not go away, it is very important to tell your Eye M.D. If you experience double vision or a droopy eyelid and have not been diagnosed with MCNP, it is critical to see your Eye M.D. as soon as possible, as these can be symptoms of a number of life-threatening conditions.