One dilated pupil, headache, face twitching, dizzy

[Mindyandboys]

Hi, 2 months ago whilst cleaning my teeth I noticed my right pupil had dilated to the point where I could hardly see the blue iris. The first time it lasted approx 30mins before returning to normal and now happens regularly but in a random fashion- I cannot provoke a reaction, it can occur in bright or dimmed light and sometimes occurs alongside other symptoms such as headache, blurred vision, facial twitching, dizziness and fatigue.
I have seen a neurologist who diagnosed migraine, and possibly an inner ear infection and she wasn't sure about my eye as it didn't dilate on the day, although the doctor who referred me had observed my pupils reacting abnormally which he called Marcus Gunn pupil. I can have medication for migraine but not until I've seen an eye specialist but I have been given something for the dizziness.
I have had an MRI and blood tests, neither of which revealed anything. I have managed to take photographs and even videos of my pupil dilating, and I am now getting a little concerned as the dizziness is getting worse (I feel like I am drunk and loose my balance a lot)
Does anyone have any thoughts what this could be? I would be most grateful for any opinions.
Thanks in anticipation

[Mindyandboys]

Thank you for your response. My dilated pupil cannot be due to eye drops as I don't use them, the only medication I take is Ramipril for high blood pressure which I have taken since I was 40 (I'm now 44) and none of my family takes any medication either as we are all generally fit and healthy. My appointment is not till the 4th June (the British health service is good but you always have to wait weeks to see any specialist )
Could I ask- how can it be migraine causing one pupil to dilate when I don't always have a headache, and why only one eye?
Thank you again

[Doreen Fazio, M.D.]

You do need to see an ophthalmologist for a work-up.  A common cause of a unilateral dilated pupil is inadvertent instillation of dilating eye drops, such as Neosynephrine, Atropine, or OTC drops which "get the red out".  If you have any of these drops at home, even if you instill them in someone else's eye, you may accidentally instill some of the medication in your eye if you touch or rub your eye.  I have seen a patient present with one dilated pupil after he placed a scopolamine patch for sea sickness behind one ear, and then touched one eye without thinking.  Do you use OTC eye drops for redness?  See the ophthalmologist for an evaluation, and let us know how you are doing.