I've used Latisse for about a week and I suddenly have blurred and double vision! Is this permanent?

Schedule a follow up with the clinic where you purchased the Latisse to discuss your concerns. Discontinue use of Latisse. Ensure you are applying the product as indicated. All the Best. 

Are you getting the Latisse into your eye? Latisse is based on a solution used to treat glaucoma but that doesn't cause blurriness or double vision either. Stop using the product if you'd like but this is not what I would consider related to your Latisse use. "This answer has been solicited without seeing this patient and
cannot be held as true medical advice, but only opinion. Seek in-person
treatment with a trained medical professional for appropriate care."