The surface of the continuously worn contact lens

The anterior surfaces of continuously worn therapeutic contact lenses and routinely cleaned cosmetic lenses were compared by scanning electron microscopy. The continuously worn lenses were uniformly and completely coated with material thicker and smoother that that on the incompletely coated cosmetic lenses. It is concluded that continuously worn lenses build up coatings steadily, whereas routinely cleaned lenses have at least part of the coating removed with each cleaning.