Inclusion Criteria:
1. Subjects already scheduled for bilateral refractive laser surgery targeting emmetropia (attempted MRSE is between and including -0.50 D and +0.50 D).
2. Minimum 18 years of age.
3. Have read, understood, and signed an informed consent form (ICF).
4. Have a stable refraction (i.e., a change of ≤ 0.50 D in sphere and cylinder) for both eyes as judged by the investigator.
5. Have less than 0.75 D spherical equivalent (SE) difference between cycloplegic and manifest refractions at preoperative visit for both eyes.
6. Study group 1 only: Have hyperopic refractive error with or without astigmatism; sphere between 0.00 D and 4.00 D, cylinder between 0.00 D and 3.00 D for both eyes; with a spherical equivalent (SE) between 0.50 D and 5.50 D for both eyes.
7. Study groups 2 and 3 only: Have myopic refractive error with or without astigmatism; sphere between -8.00 D and 0.00 D, cylinder between 0.00 D and -4.00 D for both eyes; with a spherical equivalent (SE) between -10.00 D and -1.00 D for both eyes.
8. Have CDVA of 20/25 (logMAR 0.1) or better in both eyes
9. Have normal corneal topography as determined by the Investigator for both eyes.
10. Have discontinued use of contact lenses for at least 2 weeks (for hard lenses) or 3 days (for soft lenses) prior to the pre-operative examination, and through the day of surgery.
11. All contact lens wearers must demonstrate a stable refraction (within ± 0.50 D), as determined by MRSE, on two consecutive examinations at least 1 week apart, in both eyes and the axis of cylinder should not differ by more than 15 degrees from the baseline cycloplegic refraction for both eyes.
12. Have the ability to lie flat without difficulty.
13. Are willing and able to comply with the schedule for all post-surgery follow-up visits.
Exclusion Criteria:
1. Subjects for whom the combination of their baseline corneal thickness and the planned operative parameters for the LASIK procedure would result in less than 250 microns residual stroma thickness in any eye.
2. Tear Break-Up time (TBUT) \<8 s in any eye.
3. Mesopic pupil size larger than the optical zone of the planned treatment for any eye.
4. History or evidence of active or inactive of corneal disease or infection in either eye (e.g., herpes simplex keratitis, herpes zoster keratitis, recurrent erosion syndrome, corneal dystrophy, etc.).
5. Central corneal scars affecting visual acuity or unstable keratometry with irregular mires in any eye.
6. Irregular astigmatism in any eye.
7. Keratoconus or suspicion of keratoconus (sub-clinical, forme fruste), corneal dystrophy in any eye.
8. Previous intraocular or corneal surgery in either eye that might confound the outcome of the study or increase the risk to the subject.
9. Ocular muscle disorder including a strabismus or nystagmus, or other disorder affecting fixation in any eye.
10. Evidence of retinal vascular disease in any eye.
11. History or evidence glaucoma or glaucoma suspect in any eye.
12. Acute or chronic disease or illness that would increase the operative risk, likely affect the wound healing or confound the outcomes of the study (e.g. immuno-compromised, connective tissue disease, clinically significant atopic disease, diabetes, etc.).
13. Use chronic systemic medications that may confound the outcome of the study or increase the risk to the subject, including, but not limited to steroids, antimetabolites, etc.;
14. Take medications contraindicated with LASIK such as isotretinoin (Accutane) or amiodarone hydrochloride (Cordarone).
15. Known sensitivity to medications used for standard LASIK treatment.
16. Females of childbearing potential (those who are not surgically sterilized or not postmenopausal for at least 12 months) if they meet one of the following conditions: Pregnant, lactating or unwilling to use effective birth control over the course of the study.
17. Concurrent or previous (within 30 days) participation in another drug or device investigation.
