Hwang CJ, et al. – This study is conducted to establish an initial estimation of the Minimal Clinically Important Difference (MCID) of the University of North Carolina Dry Eye Management Scale (UNC DEMS) and evaluate its relationship with patient perceptions of symptom change. The UNC DEMS is a valid, responsive patient–reported outcome measure instrument, which is easy to use in the clinic and capable of demonstrating an MCID of 1 point.