I have had cataract surgery about 4 years ago and my lens replacement were the tonic Lens, I am very happy with them. I have had several times this past month had a repeat of halo lights around my left eye that flashes. No head aches, and no vision problems, just the flasing halo. I noticed both times that if I ate a little something, they would go away with in 5-10 minutes. My blood pressure is ok, as I checked it. I do have a vision appt this month. Somehow I feel a possible low blood sugar my be the problem. I am not diabetic...