Yes, I have probably had 50 of them over 10 years. I get a little flutter in my vision and then all goes black. I can hear but not see for as long as 30 minutes. It scared me to death in the beginning. I had a brain MRI and vision tests. The neurologist called it a "silent migrane". I have met others who have it. One day I was eating lunch with two medical professonals (I am a RN). All three of us have it! I thought that was weird. I had found an herbal product at my chiropractor which helps it. It's called "Petadolex". It is a dietary supplement which is the herb Butterbur. It relaxes blood vessels in the head. You can research it at www.enzy.com or call 1-800-783-2266. It really works for me. I can stop the vision effect within 1 minute by taking this.