Purpose: To investigate whether daily-disposable and 2-week disposable soft contact lenses are being used correctly.
Methods: The number of purchases made and brands selected by the 44,566 consumers who purchased daily-disposable and 2-week disposable soft contact lenses in Okada Eye Clinic institutions between April 1, 2002 and November 1, 2002 were monitored. From the 7,759 respondents to a survey conducted in the clinic between November 1, 2002 and March 31, 2003, the number of purchases made and brands selected by the 1,584 respondents, whose sales records could be traced, were analyzed in further detail.
Results: The total number of consumers purchasing daily-disposable soft contact lenses was 14,909, and their annual average purchase was 10.56 boxes. Most purchases were of two boxes followed by purchases of four and then six. Only 6.4% of consumers purchased 24 boxes at a time. Consumers purchasing four or fewer boxes at a time accounted for 37.8%. A total of 25,705 consumers purchased 2-week disposable soft contact lenses, with an annual average purchase of 6.37 boxes per consumer. Nineteen percent of the consumers purchased eight boxes of 2-week disposable soft contact lenses per year. Most consumers tended to purchase their contact lenses in even numbers for daily-disposable and 2-week disposable soft contact lenses. Johnson & Johnson Vision Care (Jacksonville, FL) was the most popular manufacturer. According to the survey, 86.6% of the 2-week disposable soft contact lens wearers followed instructions correctly, whereas 13.4% did not. That is, they exceeded the instructed 14 days of wear.
Conclusions: Annual average purchases of daily-disposable and 2-week disposable soft contact lenses tended to be in even numbers and showed differences in their sales depending on contact lens brands. The results obtained from the survey and the actual sales records correlated.