title: The use of guide tubes and plastic covers in testing ophthalmic lenses for impact resistance.
mesh_terms: D005069:Evaluation Studies as Topic; D005139:Eyeglasses / Q000592:standards*; D006245:Hardness Tests / Q000379:methods*; D011095:Polyethylenes; D012449:Safety; D014481:United States; D014486:United States Food and Drug Administration
chemical_list: D011095:Polyethylenes