By far the most common issue is under-correction or over-correction. In this case, vision will be “good, but not perfect.” Further laser treatment, known as an “enhancement” or a “touch-up”, can improve the vision further by treating the remaining optical imperfection. About 20% of patients can experience optical consequences during the healing process, including glare, halos at night, or ghost images. In almost all cases, these disappear within several weeks or months. Careful attention to detail in centration and calibration of the laser, as well as measurement of pupil size, substantially lessens the incidence of these problems.
