For most people this surgery presents a major lifestyle improvement. BUT if perfection is demanded, surgery may not be a good choice. If uncorrected vision is less than desired and there is a treatable correction left, the flap can be lifted at a later date and more treatment administered. This additional procedure is called an enhancement and is typically performed 3-6 months after the original surgery, giving the refraction a chance to stabilize. Everyone's goal is perfect vision with one surgical procedure.
Some patients still require thinner glasses for fine-tuning their critical needs.
This is especially likely for people who had a large correction to start with. A nearsighted person, by definition, sees clearly up close. Laser treatment to restore distance vision will eliminate the ability to see up close and, for those over 40, reading glasses will be needed. The need for reading glasses is almost universal for people in their middle years. As we mature, the eye's natural lens loses its flexibility and the ability to focus decreases.