Safety and Efficacy Study of Topography-Guided LASIK to Treat Myopia and Hyperopia

Inclusion Criteria: * 18 years of age or older; * Signed Informed Consent; * Willingness and ability to comply with schedule for follow-up visits; * be a candidate for topography guided LASIK treatment of myopia or hyperopia in both eyes based on your doctors examination of your eyes; * Intended treatment is targeted for emmetropia; * Stable refraction (0.5 D or less change in manifest refraction spherical equivalent (MRSE) per year) for 12 months or longer, based on previous clinical records or prescription history (e.g., old glasses/contact lens prescriptions). * Able to obtain a reliable corneal topography that can be used to determine the T-CAT treatment plan; * Best spectacle-corrected visual acuity (BSCVA) 20/25 or better in each eye; * Less than 0.75 D spherical equivalent (SE) difference between cycloplegic and manifest refractions. * Is not a contact lens wearer or, if wearing contact lenses, has discontinued wearing contact lenses for the required period of time and completed the contact lens stability check; * be able to maintain your eye position steady during the course of the treatment. Exclusion Criteria: * History of prior refractive treatment; * Mixed astigmatism refractive error; * Lenticular astigmatism that, in the investigator's opinion, is clinically significant; * Corneal topography showing evidence of keratoconus, keratoconus suspect, forme fruste keratoconus, pellucid marginal degeneration, or other topographic abnormality that would place the eye at risk for developing post-refractive corneal ectasia; * Treatment plan for T-CAT would predict a residual stromal bed thickness less than 250 microns; * History or current evidence of corneal or other anterior segment disease that might reasonably be expected to affect the outcome of treatment (e.g., herpes simplex keratitis, herpes zoster keratitis, recurrent erosion syndrome, corneal melt, corneal dystrophy, etc.); * Evidence of retinal vascular disease; * Female patients who are pregnant or lactating or plan to become pregnant during the course of the study; * A known sensitivity to study medications; * Nystagmus or any other condition that would prevent a steady gaze during the LASIK treatment or other diagnostic tests; * Corneal dystrophy or corneal guttae; * Pathology involving the iris (e.g., coloboma, tears, cuts, significant pigment loss, etc.); * Residual, recurrent or active ocular pathology; * Previous intraocular or corneal surgery that might confound the outcome or increase the risk of the study; * Acute or chronic illness that might increase the risk or confound the outcome of the study (e.g., diagnosed autoimmune disease, systemic connective tissue disease, clinically significant atopic disease, diabetes mellitus, etc.) * The use of systemic medications that may confound the outcome or increase the risk of the study, including, but not limited to: corticosteroids and antimetabolites; * Intraocular pressure \> 23 mm Hg, a history of glaucoma, or a glaucoma suspect; * An increased risk for developing strabismus after treatment (applicable only to treatment of hyperopic refractive errors); * Presence or history of any other condition or finding that, in the investigator's opinion, makes the patient unsuitable as a candidate for LASIK or study participation or may confound the outcome of the study.