Ocular Evidence
Procedures / LASIK
Corneal laser

LASIK outcomes

An excimer laser reshapes corneal stromal tissue after a corneal flap is created; the flap is then repositioned.

Source: U.S. Food and Drug Administration
Find overlapping cohorts
11studies represented
12study arms
31,146reported enrolled eyes*
2 yearslongest standardized follow-up

* Descriptive sum of reported arm counts. Missing eye counts are not treated as zero, and overlapping cohorts may not be additive.

How the operation changes the eye
Three-stage medical illustration showing a LASIK corneal flap lifted, laser reshaping beneath the flap, and the flap repositioned
Original explanatory illustration. Simplified anatomy; exact devices and technique vary.
How the operation works

A flap is lifted, then the cornea is reshaped

LASIK changes the focusing power of the cornea by removing a planned amount of tissue beneath a thin hinged flap.

  1. A thin, hinged flap is created in the front of the cornea.
  2. The flap is lifted and an excimer laser reshapes the exposed stromal tissue.
  3. The flap is placed back over the treated area; stitches are usually not needed.
Clinical reference: US FDA — What is LASIK?

Study-specific outcomes

Percentages are displayed individually. They are not pooled or averaged.

MODERATE evidenceRETROSPECTIVEVerified evidence

Incidence, severity, and predictors of early postoperative dry eye disease following femtosecond laser-assisted in situ keratomileusis (FS-LASIK): a short-term, single-center retrospective analysis (2026)

FS-LASIK cohortEye count not reportedDevice not reported
1 week3000 patients observed
Not reportedUncorrected 20/20 or better
Not reportedRefraction within ±0.50 D
Not reportedRefraction within ±1.00 D
Not reportedLost at least 2 lines of CDVA
Additional source-reported outcomes
25.0%
3000 patients
Source · Abstract
Dry eye symptoms (OSDI ≥13)
1 month3000 patients observed
Not reportedUncorrected 20/20 or better
Not reportedRefraction within ±0.50 D
Not reportedRefraction within ±1.00 D
Not reportedLost at least 2 lines of CDVA
Additional source-reported outcomes
38.0%
3000 patients
Source · Abstract
Dry eye symptoms (OSDI ≥13)
3 months3000 patients observed
Not reportedUncorrected 20/20 or better
Not reportedRefraction within ±0.50 D
Not reportedRefraction within ±1.00 D
Not reportedLost at least 2 lines of CDVA
Additional source-reported outcomes
15.0%
3000 patients
Source · Abstract
Dry eye symptoms (OSDI ≥13)
HIGH evidenceFDA PIVOTALVerified evidence

FDA pivotal clinical study of INNOVEYES LASIK with WaveLight EX500 (2025)

INNOVEYES LASIK336 enrolled eyesWaveLight EX500 with INNOVEYES Sightmap
3 months326 eyes observed
92.3%
301/326 eyes
Source · 25
Uncorrected 20/20 or better
92.0%
300/326 eyes
Source · 23
Refraction within ±0.50 D
98.5%
321/326 eyes
Source · 23
Refraction within ±1.00 D
0%
0/330 eyes
Source · 15
Lost at least 2 lines of CDVA
6 months330 eyes observed
91.5%
302/330 eyes
Source · 25
Uncorrected 20/20 or better
90.9%
300/330 eyes
Source · 24
Refraction within ±0.50 D
98.2%
324/330 eyes
Source · 24
Refraction within ±1.00 D
Not reportedLost at least 2 lines of CDVA
12 months322 eyes observed
94.4%
304/322 eyes
Source · 25
Uncorrected 20/20 or better
94.4%
304/322 eyes
Source · 24
Refraction within ±0.50 D
99.7%
321/322 eyes
Source · 24
Refraction within ±1.00 D
Not reportedLost at least 2 lines of CDVA
LOW evidenceRETROSPECTIVEVerified evidence

Myopic Regression After FS-LASIK and SMILE (2024)

Matched FS-LASIK cohort416 enrolled eyesDevice not reported
3 months416 eyes observed
Not reportedUncorrected 20/20 or better
Not reportedRefraction within ±0.50 D
Not reportedRefraction within ±1.00 D
Not reportedLost at least 2 lines of CDVA
Additional source-reported outcomes
Spherical-equivalent regression from month 1
6 months416 eyes observed
Not reportedUncorrected 20/20 or better
Not reportedRefraction within ±0.50 D
Not reportedRefraction within ±1.00 D
Not reportedLost at least 2 lines of CDVA
Additional source-reported outcomes
Spherical-equivalent regression from month 1
9 months416 eyes observed
Not reportedUncorrected 20/20 or better
Not reportedRefraction within ±0.50 D
Not reportedRefraction within ±1.00 D
Not reportedLost at least 2 lines of CDVA
Additional source-reported outcomes
Spherical-equivalent regression from month 1
12 months416 eyes observed
Not reportedUncorrected 20/20 or better
Not reportedRefraction within ±0.50 D
Not reportedRefraction within ±1.00 D
Not reportedLost at least 2 lines of CDVA
Additional source-reported outcomes
Spherical-equivalent regression from month 1
18 months416 eyes observed
Not reportedUncorrected 20/20 or better
Not reportedRefraction within ±0.50 D
Not reportedRefraction within ±1.00 D
Not reportedLost at least 2 lines of CDVA
Additional source-reported outcomes
Spherical-equivalent regression from month 1
HIGH evidenceRCTVerified evidence

Randomized Clinical Trial Comparing Femtosecond LASIK and Small-Incision Lenticule Extraction (2020)

Femtosecond LASIK70 enrolled eyesWaveLight EX500
3 months70 eyes observed
87.0%
70 eyes
Source
Uncorrected 20/20 or better
Not reportedRefraction within ±0.50 D
97.0%
70 eyes
Source
Refraction within ±1.00 D
Not reportedLost at least 2 lines of CDVA
Additional source-reported outcomes
Efficacy index
Safety index
12 months70 eyes observed
83.0%
70 eyes
Source
Uncorrected 20/20 or better
Not reportedRefraction within ±0.50 D
99.0%
70 eyes
Source
Refraction within ±1.00 D
Not reportedLost at least 2 lines of CDVA
Additional source-reported outcomes
Safety index
MODERATE evidencePROSPECTIVE COHORTVerified evidence

Symptoms and Satisfaction of Patients in the Patient-Reported Outcomes With Laser In Situ Keratomileusis (PROWL) Studies (2017)

PROWL-1 military cohortEye count not reportedDevice not reported
3 monthsFollow-up sample not reported
Not reportedUncorrected 20/20 or better
Not reportedRefraction within ±0.50 D
Not reportedRefraction within ±1.00 D
Not reportedLost at least 2 lines of CDVA
Additional source-reported outcomes
Normal OSDI score
6 monthsFollow-up sample not reported
Not reportedUncorrected 20/20 or better
Not reportedRefraction within ±0.50 D
Not reportedRefraction within ±1.00 D
Not reportedLost at least 2 lines of CDVA
Additional source-reported outcomes
Normal OSDI score
MODERATE evidencePROSPECTIVE COHORTVerified evidence

Symptoms and Satisfaction of Patients in the Patient-Reported Outcomes With Laser In Situ Keratomileusis (PROWL) Studies (2017)

PROWL-2 civilian cohortEye count not reportedDevice not reported
3 monthsFollow-up sample not reported
Not reportedUncorrected 20/20 or better
Not reportedRefraction within ±0.50 D
Not reportedRefraction within ±1.00 D
Not reportedLost at least 2 lines of CDVA
Additional source-reported outcomes
Normal OSDI score
MODERATE evidencePROSPECTIVE COHORTVerified evidence

Chronic dry eye in photorefractive keratectomy and laser in situ keratomileusis: Manifestations, incidence, and predictive factors (2015)

LASIK cohortEye count not reportedDevice not reported
12 monthsFollow-up sample not reported
Not reportedUncorrected 20/20 or better
Not reportedRefraction within ±0.50 D
Not reportedRefraction within ±1.00 D
Not reportedLost at least 2 lines of CDVA
Additional source-reported outcomes
Chronic dry-eye incidence
MODERATE evidencePROSPECTIVE COHORTVerified evidence

Dry Eye Disease following Refractive Surgery: A 12-Month Follow-Up of SMILE versus FS-LASIK in High Myopia (2015)

FS-LASIK high-myopia cohort43 enrolled eyesDevice not reported
1 month43 eyes observed
Not reportedUncorrected 20/20 or better
Not reportedRefraction within ±0.50 D
Not reportedRefraction within ±1.00 D
Not reportedLost at least 2 lines of CDVA
Additional source-reported outcomes
6.53 s
43 patients
Source · Table 3
Tear breakup time
1.56
43 patients
Source · Table 4
Salisbury Eye Evaluation Questionnaire dry-eye score
3 months43 eyes observed
Not reportedUncorrected 20/20 or better
Not reportedRefraction within ±0.50 D
Not reportedRefraction within ±1.00 D
Not reportedLost at least 2 lines of CDVA
Additional source-reported outcomes
7.42 s
43 patients
Source · Table 3
Tear breakup time
1.21
43 patients
Source · Table 4
Salisbury Eye Evaluation Questionnaire dry-eye score
6 months43 eyes observed
Not reportedUncorrected 20/20 or better
Not reportedRefraction within ±0.50 D
Not reportedRefraction within ±1.00 D
Not reportedLost at least 2 lines of CDVA
Additional source-reported outcomes
8.19 s
43 patients
Source · Table 3
Tear breakup time
0.49
43 patients
Source · Table 4
Salisbury Eye Evaluation Questionnaire dry-eye score
12 months43 eyes observed
Not reportedUncorrected 20/20 or better
Not reportedRefraction within ±0.50 D
Not reportedRefraction within ±1.00 D
Not reportedLost at least 2 lines of CDVA
Additional source-reported outcomes
9.30 s
43 patients
Source · Table 3
Tear breakup time
0.14
43 patients
Source · Table 4
Salisbury Eye Evaluation Questionnaire dry-eye score
MODERATE evidencePROSPECTIVE COHORTVerified evidence

Single-Step Transepithelial ASLA (SCHWIND) With Mitomycin-C for the Correction of High Myopia: Long-Term Follow-Up (2015)

LASIK31 enrolled eyesAMARIS
12 months31 eyes observed
Not reportedUncorrected 20/20 or better
Refraction within ±0.50 D
Not reportedRefraction within ±1.00 D
Not reportedLost at least 2 lines of CDVA
Additional source-reported outcomes
-0.08 D
31 eyes
Source · Abstract
Mean postoperative spherical equivalent
0.050 logMAR
31 eyes
Source · Abstract
Mean uncorrected distance visual acuity
HIGH evidenceRCTVerified evidence

Comparison of visual and refractive outcomes following femtosecond laser-assisted LASIK with SMILE in patients with myopia or myopic astigmatism (2014)

Femtosecond LASIK50 enrolled eyesDevice not reported
1 day50 eyes observed
Uncorrected 20/20 or better
Not reportedRefraction within ±0.50 D
Not reportedRefraction within ±1.00 D
Not reportedLost at least 2 lines of CDVA
3 months50 eyes observed
Uncorrected 20/20 or better
Not reportedRefraction within ±0.50 D
Not reportedRefraction within ±1.00 D
Not reportedLost at least 2 lines of CDVA
MODERATE evidencePROSPECTIVE COHORTVerified evidence

Comparison of dry eye and corneal sensitivity between small incision lenticule extraction and femtosecond LASIK for myopia (2013)

Femtosecond LASIK33 enrolled eyesDevice not reported
1 week32 eyes observed
Not reportedUncorrected 20/20 or better
Not reportedRefraction within ±0.50 D
Not reportedRefraction within ±1.00 D
Not reportedLost at least 2 lines of CDVA
Additional source-reported outcomes
18.78
32 patients
Source · Table 3
Ocular Surface Disease Index
4.70 s
32 patients
Source · Table 3
Tear breakup time
10.00 mm
32 patients
Source · Table 3
Schirmer I test without anesthesia
1 month31 eyes observed
Not reportedUncorrected 20/20 or better
Not reportedRefraction within ±0.50 D
Not reportedRefraction within ±1.00 D
Not reportedLost at least 2 lines of CDVA
Additional source-reported outcomes
17.77
31 patients
Source · Table 3
Ocular Surface Disease Index
3.77 s
31 patients
Source · Table 3
Tear breakup time
10.90 mm
31 patients
Source · Table 3
Schirmer I test without anesthesia
3 months30 eyes observed
Not reportedUncorrected 20/20 or better
Not reportedRefraction within ±0.50 D
Not reportedRefraction within ±1.00 D
Not reportedLost at least 2 lines of CDVA
Additional source-reported outcomes
16.22
30 patients
Source · Table 3
Ocular Surface Disease Index
4.43 s
30 patients
Source · Table 3
Tear breakup time
13.73 mm
30 patients
Source · Table 3
Schirmer I test without anesthesia
6 months30 eyes observed
Not reportedUncorrected 20/20 or better
Not reportedRefraction within ±0.50 D
Not reportedRefraction within ±1.00 D
Not reportedLost at least 2 lines of CDVA
Additional source-reported outcomes
15.50
30 patients
Source · Table 3
Ocular Surface Disease Index
4.97 s
30 patients
Source · Table 3
Tear breakup time
13.17 mm
30 patients
Source · Table 3
Schirmer I test without anesthesia