Wavefront technology is helpful in retreating problems that may result from LASIK. Occasionally, patients develop problems with quality of nighttime or daytime vision after undergoing LASIK surgery. These problems are usually caused by higher-order aberrations. Therapeutic wavefront-guided retreatment is a process employed by experienced surgeons during which wavefront technology is used to measure these higher-order aberrations; then the data gleaned from the wavefront technology are used to perform a LASIK retreatment. This application of wavefront technology can be used to treat many potential LASIK side effects, such as halos, multiple images, undercorrection, and glare.