The dehydrated surface of a commercially available contact lens containing hydroxyethyl methacrylate and phosphorylcholine is investigated by time of flight secondary ion mass spectrometry employing a 25keV Bi3+ ion beam. Results show the successful detection of hydroxylethyl methacrylate and phosphorylcholine species from an Omafilcon A lens. Utilization of a 20keV C60 ion beam allowed the bulk region of the lenses to be probed using primary ion dose densities exceeding 2×1014C60∕cm2 and indicated that the phosphorylcholine component reorganizes below the surface. X-ray photoelectron spectroscopy results are consistent with the presence of these moieties and suggest that the phosphorylcholine components may be below 100Å in the dehydrated hydrogel.