Based on the eye movement data of subjects detected by eye tracker， a new eye movement index， the percentage change of eyelid spacing， is put forward. Then it is compared with such traditional eye movement indices as saccade count and pupil diameter. After significance and correlation analysis， the receiver operating characteristic （ROC） curve is used to evaluate the discriminant performance of every eye movement on the lens comfort. Experimental results show that the proposed percentage change of eyelid spacing is the best indicator to evaluate the lens comfort， followed by the pupil diameter， and the saccade index and the average fixation duration are the similar. It validates that the lens comfort can be evaluated accurately and quickly by detecting the percentage change of eyelid spacing of subjects. This research can help relevant practitioners to evaluate the lens comfort from an objective perspective， and also provides some technical and theoretical help for increasingly severe myopia prevention and control situation of China.