Two different types of polishing solutions are being evaluated for possible use in a tumble-polish operation for manufacturing intraocular lenses used in the human eye following cataract surgery. 300 lenses were tumble-polished using the first polishing solution, and of this number, 254 had no polishing-induced defects. another 300 lenses were tumble-polished using the second polishing solution, and 193 lenses were satisfactory upon completion. is there any reason to believe that the two polishing solutions differ