I have been getting these off and on more in one eye then the other for the past several years. This year tho I have had one difference. The floaters in the new eye to be affected are proceeded by a day or two of nystagmus. This is a horizontal rapid oscilliation in this case. I don't know what causes that part. Once the floaters were fairly massive. They do tend to fade over time and go away. Sometimes there is more time between new events. The first time it happened I was rather startled by it and called my eye doctor. He had me come in so he could examine my eyes. He told me to watch out for flashes of light and if that ever happened I was to come in immediately as it might be a detatched retina. I have never had that happen tho thank goodness.