Should successful monovision contact lens wearers be refitted with bifocal lenses?
METHODS: Fifty current monovision lens wearers were fitted with ACUVUE Bifocal contact lenses (Johnson & Johnson Vision Care, Jacksonville, FL). Visual function and subjective vision ratings were assessed with habitual monovision lenses at the first visit and then were repeated at the end of 6 months while wearing bifocal lenses. Lens preference was determined at the end of the 6-month study, and the subjects were called 1 year later to repeat the lens preference questionnaire. RESULTS: Forty (80%) subjects completed the 6-month study; nine discontinued for visual reasons. At the end of 6 months of wear, 68% preferred bifocal lenses and 25% preferred monovision. Of the subjects who were contacted a year later, 53% were still wearing bifocal lenses. High-contrast visual acuity and letter contrast sensitivity at distance was the same for monovision and bifocal lenses, but low-contrast acuity was better with monovision. Intermediate low- and high-contrast acuity and 3-meter and near stere