An epiretinal membrane, also called a macular pucker, is a condition in which a thin membrane covers the surface of the macula due to cellular proliferation and collagen deposition. The macula is the area of the retina—the eye’s neural layer—where 90% of the cells that detect bright light are concentrated; it is the focal point and the most important area for forming central vision. When an abnormal membrane that should not be there grows over this area, it pulls on the macular nerve layer, causing the macula to swell (macular edema) or wrinkle, and the nerve layer is gradually damaged.