Effects of different contact lens materials and contact lens-wearing periods on conjunctival cytology in asymptomatic contact lens wearers.

Purpose: To investigate the conjunctival cytologic changes induced by different contact lens materials and contact lens-wearing periods in asymptomatic contact lens wearers.

Methods: Seventy-five patients (150 eyes) who were to wear contact lenses for the first time were evaluated in this study. Forty eyes of 20 soft hydroxyethylmethacrylate (vinyl pyrrolidone copolymer) contact lens wearers, 70 eyes of 35 soft Polymacon contact lens wearers, and 40 eyes of 20 hard gas-permeable contact lens wearers used the lenses on a daily-wear basis.