Determinants of the frequency of contact lens wear

To characterize and discover the determinants of the frequency of wear (FOW) of contact lenses.

Survey forms were sent to contact lens fitters in up to 40 countries between January and March every year for 5 consecutive years (2007-2011). Practitioners were asked to record data relating to the first 10 contact lens fits or refits performed after receiving the survey form. Only data for daily wear lens fits were analyzed.

Data were collected in relation to 74,510 and 9,014 soft and rigid lens fits, respectively. Overall, FOW was 5.9±1.7 days per week (DPW). When considering the proportion of lenses worn between one to seven DPW, the distribution for rigid lenses is skewed toward full-time wear (7 DPW), whereas the distribution for soft daily disposable lenses is perhaps bimodal, with large and small peaks at seven and two DPW, respectively. There is a significant variation in FOW among nations (P<0.0001), ranging from 6.8±1.0 DPW in Greece to 5.1±2.5 DPW in Kuwait. For soft lenses, FOW increases with decreasing age. Females (6.0±1.6 DPW) wear lenses more frequently than males (5.8±1.7 DPW) (P=0.0002). FOW is greater among those wearing presbyopic corrections (6.1±1.4 DPW) compared with spherical (5.9±1.7 DPW) and toric (5.9±1.6 DPW) designs (P<0.0001). FOW with hydrogel peroxide systems (6.4±1.1 DPW) was greater than that with multipurpose systems (6.2±1.3 DPW) (P<0.0001).

Numerous demographic and contact lens-related factors impact FOW. There may be a future trend toward a lower FOW associated with the increasing popularity of daily disposable lenses.