OBJECTIVE To investigate the changes in functional visual acuity (VA) and higher order aberrations in dry eye patients. METHODS In this prospective comparative case series, 22 right eyes were classified into those with or without superficial punctate keratopathy (SPK) in the central cornea of 22 patients with Sjögren syndrome; 10 right eyes of 10 normal subjects served as the control. Serial measurements of VAs using a functional VA measurement system and higher order aberrations using a wavefront sensor were performed under blink-free conditions without topical anesthesia over a 10-second period. The parameters for each measurement were compared among the SPK-positive and -negative and normal groups. The correlation between those parameters was also analyzed. RESULTS Dry eye with SPK showed significant deterioration of visual function and optical quality compared with dry eye without SPK and in normal eyes, as detected by both the visual maintenance ratio (VMR; P < 0.05) and the variation of VA (P < 0.05) and by comalike and total higher order aberrations (P < 0.05). Moreover, the severity of epithelial damage at the central cornea correlated significantly with VMR (P < 0.01) and variation of VA (P < 0.01) as well as comalike (P < 0.05) and total higher order aberrations (P < 0.05). The dry eye group without SPK showed minor visual deterioration compared with normal eyes, as detected only by VMR (P < 0.05). CONCLUSIONS Optical disturbances at the central optical zone of the cornea in dry eye disease may affect visual performance. Functional VA measurement may be an applicable method of evaluating visual performance in dry eyes that is as efficient as wavefront aberration measurements.