This study evaluates the reliability, validity and safety of a self administered, subjective refraction test via a mobile medical app (GoEyes) as compared to standard of care subjective manifest refraction performed by a health care provider, in subjects who have no known ocular disease or condition other than refractive error.

GoEyes is a Mobile Medical Application, which can be downloaded to a smartphone and is being developed as a self -administered subjective refraction examination that measures the refractive error of the user's eyes in the home environment without any contact or help from health care professionals.

The Study will be conducted in 2 parts; Part 1 and Part 2.

Approximately 59 participants will be enrolled In Part 1. Part 1 participants will have a GoEyes refraction test in clinic on two separate days and will also have a standard of care refraction test performed by a health care provider and best corrected visual acuity assessments.

Approximately 349 participants will be enrolled in Part 2. Part 2 participants will self administer the GoEyes test at home on 2 separate days and will also have in clinic standard of care refraction test performed by a health care provider and best corrected visual acuity assessments.

Inclusion Criteria:

1. Males or females aged 18-39 years who currently wear glasses and/or soft contact lenses to correct refractive error
2. Normal color vision
3. Able to use both hands at the same time and to hear, understand and verbally respond to audio instructions
4. Have single vision lenses only
5. Able to provide informed consent -

Exclusion Criteria:

1. Have any ongoing disease or ocular condition other than refractive error
2. Have a history of permanent vison loss
3. Have a neurological condition affecting vision
4. Have worn glasses since age 6 or younger
5. Have a prism in their prescription
6. Use Rigid gas permeable lenses or OrthoK lenses
7. Have had laser refractive surgery or any other eye surgery
8. Use prescription eye drops -

The Best Corrected Visual Acuity (BCVA) assessor will be masked to GoEyes and Standard of Care refraction results.