Study of a Hand-held Device Plus Mobile App Versus Standard Eye Care Devices in Measuring Refractive Error of the Eye

Inclusion Criteria: * Male or Female * Age 30 through 65 years at the time of consent * Binocular vision * Subject desires refraction for correction of visual acuity and vision can be corrected in each eye to 20/20 (LogMAR 0.0) * Willing and able to give informed consent and follow all study procedures and requirements * Ability to speak and understand the English language Exclusion Criteria: * Spherical correction \> +8 or \< -10 * Using anticholinergic medications (including first-generation antihistamines) or other medications known to affect visual acuity within the greater of 3 days or 5 half-lives prior to enrolling in this study * Using an investigational drug or approved therapy for investigational use within the greater of 3 days or 5 half-lives prior to enrolling in this study * Has initiated any new medication in the past 2 weeks that, in the best medical judgment of the investigator, would impact their participation in the study or ability to use the device * Eye disease, including but not limited to: * Glaucoma (≥ 22 mmHg intraocular pressure) * Cataracts (≥ 1+ nuclear sclerotic cataract, ≥ 1+ cortical, posterior subcapsular cataract \[any grade using the Lens Opacities Classification System III\]) * Macular degeneration (retinal pigmented epithelium mottling and/or any drusen within 500 μm of macula) * Eye infection (corneal ulcer, corneal infiltrates, superficial punctate keratitis) * Keratoconus * Diabetic neuropathy/retinopathy (≥ mild nonproliferative diabetic retinopathy) * Cytomegalovirus retinitis * Color blindness (any color deficiency) * Diabetic macular edema (evidence of fluid) * Amblyopia * Chronic or acute uveitis (cells and/or flare in anterior chamber) * Strabismus (exotropia, esotropia, and hypertropia) * Abnormal astigmatism (mild to severe, \> 5 diopters) * Macular hole * Eye surgery within the last 12 months (including Lasik or lens replacement) * Subject does not have the physical dexterity to properly operate the device or the on the smartphone in the investigator's opinion.