Occasionally, after a PVD, microbreaks along the surface of the retina allows cells to migrate along the retinal surface. The cells are called glial cells and have the ability to replicate and contract. They often times grow over the macula as a thin transparent sheet that has no visual consequence. In some patients, this sheet of cells contract and distorts the retinal tissue and causes retinal swelling. The distorted macula and swelling results in blurred vision or distorted wavy vision. Treatment requires surgery with a vitrectomy/membrane peel to remove this sheet of cells to restore normal retinal architecture.