Ocular Surface Comfort During the Day Assessed by Instant Reporting in Different Types of Contact and Non–Contact Lens Wearers

OBJECTIVE: To compare instant reporting of comfort throughout the day in hydrogel, silicone-hydrogel, gas-permeable, and non-contact lens wearers. METHODS: More than twenty subjects were recruited per group. Comfort scores were recorded using short message service (text message) in the morning (9:00-11:00 am), afternoon (2:00-4:00 pm), and night (7:00-9:00 pm) using a 0 (causes pain) to 100 (excellent) scale. RESULTS: The pooled comfort scores across all groups and time periods revealed that data are skewed toward high values: 88% of the scores felt between >or=70 and 100, whereas the remaining 12% felt between >or=40 and <70. Comfort changed significantly over time (P=0.003), but no significant differences were found between groups (P=0.66) or in the interaction between time and group (P=0.79). Hydrogel and silicone-hydrogel contact lens-wearing groups showed similar reductions in afternoon (-4.5 +/- 11.8 and -4.5 +/- 8.6, respectively) and night comfort scores (-8.3 +/- 14.1 and -9.1 +/- 8.7, respectively), and these were greater than those found in gas-permeable and non-contact lens wearers both in the afternoon (-1.0 +/- 11.3 and -1.8 +/- 16.3, respectively) and night (-7.3 +/- 9.7 and -4.1 +/- 21.9, respectively). DISCUSSION: Hydrogel and silicone-hydrogel contact lens wearers' comfort scores are reduced at night compared with morning. The slight comfort reduction at night versus morning found in non-contact lens wearers might be related to ocular or general physical fatigue, which suggest the possibility that reduced end-of-day comfort reported by contact lens wearers might not be solely related to contact lens wear. The results of this study also suggest that interpretation of comfort scores should be carried out with caution.