Microscratch resistance of ophthalmic coatings on organic lenses

The mechanical properties, the scratch resistance and the surface damage mechanisms of organic lenses and transparent anti-scratch and antireflective coatings, commonly used in ophthalmic industry, have been studied by means of instrumented nanoindentation and microscratch testing. The effect of the tip microscratch velocity on the mechanical response of a polymeric commercial lens has been qualitatively explained in terms of Eyring's formalism. The analysis of the mean residual scratch depth is proposed as a powerful characterization technique to foresee the Bayer abrasion resistance of ophthalmic coatings. ► Scratch resistance of ophthalmic coatings is studied by using microscratch testing. ► The Bayer abrasion resistance is predicted by the study of the residual scratch depth. ► Surface damage and fracture mechanisms of ophthalmic coatings are identified. ► The effect of the tip scratch velocity is explained in terms of Eyring's formalism.