The patients in this study entered it so nearsighted that none of them would have been able to make out even the big "E" at the top of the eye chart. The average beginning eyeglass correction to achieve normal vision was about -14.00 diopters. On average, by three months after surgery, the patients' vision was normal, with no eyeglass correction needed for good vision. Finally, by 10 years after surgery, the average correction reverted to about -2.00 diopters (that is, mildly nearsighted). To get a sense of what this means, go to the reading-glass department of your local drugstore or supermarket and try on a pair of +2.00 readers. Look around, up close and at a distance: That's what the world looks like to a nearsighted person who needs -2.00 diopters of correction to achieve perfect vision.