By the mid-1990s, in most countries, the prescribing of extended-wear contact lenses was very unusual, principally due to the generally unsatisfactory clinical performance of soft lenses worn for that modality at the time (Morgan & Efron 2006). As such, the launch of silicone hydrogel contact lenses for extended wear in 1999 was greeted with considerable interest by the contact lens professions, keen to understand the overall performance of these new lenses in addition to the nature and the incidence of any related clinical adverse events.