SMILE: Flapless Laser Vision Correction

How SMILE works

The femtosecond laser can focus its pulses at a precise depth inside the cornea. In SMILE it uses that ability in three steps: first to define the lower surface of a lenticule, then its upper surface, and finally to cut a small incision at the edge. The lenticule's shape is calculated from your prescription, so removing it changes the cornea's curvature by exactly the amount needed to correct your vision. The surgeon separates the lenticule with a fine instrument and draws it out through the incision. The whole treatment takes about 30 seconds of laser time per eye.

How SMILE differs from LASIK and PRK

LASIK reaches the cornea by lifting a flap about 20 millimeters around; SMILE reaches it through an incision of 2 to 4 millimeters. That leaves the cornea's front layers, and the nerves that run through them, largely intact. In practice that means less dryness in the first months, no flap to displace, and a cornea that retains more of its structural strength. PRK has no flap either, but it removes the surface layer and heals over days; SMILE leaves the surface in place and is comfortable within a day or two.

Who SMILE suits

SMILE is a good fit for patients who:

• Are nearsighted up to about -10 diopters, with or without up to about 3 diopters of astigmatism, within the approved range
• Have dry eye or are concerned about post-LASIK dryness
• Play contact sports or work in roles where a flap could be a liability
• Prefer a single-laser, flapless procedure

SMILE does not currently treat farsightedness, and very low prescriptions are often better served by LASIK. As with every procedure here, your measurements decide the recommendation.

Results

SMILE has been performed on millions of eyes worldwide and studies show visual outcomes comparable to LASIK, with lower rates of dry eye symptoms in the first six months. Vision is usually clear within a day or two, sharpening over a few weeks. Enhancements, if ever needed, are done with a surface treatment.