The macula is the area of the retina that is responsible for clear vision. As a person ages, the vitreous inside of the eye begins to shrink. When this occurs in the macular area, the retina initiates a healing response with a migration of cells found within the retina itself. These cells form a thin layer of scar tissue known as a macular pucker or epiretinal membrane.
Learn more at the American Academy of Ophthalmology website.