Han T, et al. - In this prospective clinical study, researchers determined alterations in objective disk halo size generated by a glare source following small incision lenticule extraction (SMILE) for myopia correction. Overall 45 right eyes of 45 patients with a mean age of 25.40 ± 5.06 years and mean spherical equivalent (SE) of − 6.08 ± 1.90 diopters were analyzed. Using a vision monitor, the measurements of disk halo size were obtained prior to surgery and at postoperative 1 week and 3 months. Following SMILE, a temporary increase was shown by disk halo size, which then rebounded to baseline. A significant correlation with SE, minimum pupil size, and average pupil size was demonstrated by preoperative disk halo size. A significant correlation of disk halo size, at postoperative 1 week, with age and minimum pupil size, was also revealed. Significant correlation with lenticule diameter, initial diameter, maximum pupil size, minimum pupil size, and average pupil size was demonstrated by disk halo size at postoperative 3 months.