A Randomized Trial on the Benefits of Refitting Symptomatic Contact Lens Wearers with Daily Disposable Lenses

<b>Background/Objective</b>: Contact lens discomfort (CLD) is a prevalent issue affecting up to 50% of wearers and contributes to discontinuation in approximately 30% of cases. This study aimed to evaluate the impact of refitting symptomatic monthly replacement contact lens (CL) wearers with a new daily, disposable contact lens (Kalifilcon A DDCL) and to compare its effectiveness against a placebo CL. <b>Methods</b>: Seventy-nine symptomatic wearers (CLDEQ-8 ≥ 12; mean age 27.07 ± 8.38 years; 77% female) were recruited and randomly assigned to wear either Kalifilcon A DDCLs or placebo CLs. Participants were assessed at baseline and after one month of CL wear. Subjective measures included the CLDEQ-8 and the NEI VFQ-25 questionnaire. Objective assessments included tear film stability and ocular surface health. Statistical analysis was performed using paired <i>t</i>-tests and repeated-measures ANOVA. Bonferroni correction was applied for multiple comparisons, and results were reported with effect sizes (Cohen's d) and 95% confidence intervals. Statistical significance was set at <i>p</i> < 0.05. <b>Results</b>: Kalifilcon A DDCL wearers showed a significant reduction in CLDEQ-8 scores (18.5 ± 4.6 to 10.8 ± 8.5; <i>p</i> < 0.005; Cramer's V: 0.594; 95% CI: 13.35-15.34), with only 33% remaining symptomatic. Vision-related quality of life improved (75.83 ± 8.0 to 83.5 ± 8.6; <i>p</i> < 0.005; Cramer's V: 0.977; 95% CI: 78.54-80.81), especially in ocular pain (<i>p</i> < 0.001; Cramer's V: 0.755; 95% CI: 54.73-58.88), role difficulties (<i>p</i> < 0.001; Cramer's V: 0.812; 95% CI: 35.12-42.77), and color vision (<i>p</i> < 0.05; Cramer's V: 0.575; 95% CI: 93.07-95.63). Compared to the placebo CL, Kalifilcon A DDCLs led to greater improvements in comfort (<i>p</i> < 0.0001; Cramer's V: 0.329; 95% CI: 7.22-7.74), visual acuity (<i>p</i> < 0.0001; Cramer's V: 0.267; 95% CI: 7.38-7.85), and satisfaction (<i>p</i> = 0.005; Cramer's V: 0.208; 95% CI: 7.70-8.18). Tear film stability also improved significantly (<i>p</i> < 0.05), with no changes observed in the placebo group. <b>Conclusions</b>: Refitting symptomatic CL wearers with Kalifilcon A DDCLs significantly improves comfort, reduces CLD symptoms, and enhances vision-related quality of life. These results support its use as a beneficial alternative to monthly CLs in symptomatic individuals.