Recent Android mobile device technology is available which allows user-measured refractive error and reading add power. This technology could be quite useful to the clinical and research community. The current study aims to evaluate the accuracy, repeatability, and reproducibility of one such technology by VisionApp, specifically with regard to ghosting vision.

VisionApp is an app which runs on a smartphone or other device which uses the distance between the user's face and the phone to determine refractive error, while the user looks at different targets (lines, letters, words, etc).

Subjects will be enrolled at the Clinical Optics Research Lab at Indiana University.

At the study visit, demographic and health/ocular history may be collected by oral history and standard clinical testing including refraction (check of glasses prescription), auto-refraction or abbrerometry may be performed. Visual acuity and room lighting checks may also be measured using standard clinical techniques.

For the experimental portion of the study visit, participants will be asked to look at letters and describe any shadows or distortions they see using slider bars or numerical rating scales, while wearing different contact lenses. Participants will first be asked to wear commercially available single vision contact lenses to establish best corrected vision. A single vision lens will then remain in one eye, and participants will proceed with ghosting assessments using two different multifocal contact lenses worn in the other eye. Adult participants will perform the ghosting assessments while wearing 2 commercially available multifocal lenses, and children participants will perform the ghosting assessments while wearing a commercially available and investigational lens. Randomization will determine which lens is worn first.

If participants are unable to complete all testing in a single session, they may be permitted to return on a subsequent day.

Inclusion Criteria:

• has a refractive error between Plano and -5.00 D of sphere and cylinder components combined.
• has refractive cylinder (e.g., astigmatism) of -0.75 D or less
• has had a self-reported oculo-visual exam in the last 2 years
• has best-corrected visual acuity of at least 20/20 in each eye
• is not amblyopic or does not have any diagnosed ocular disease
• is willing and able to follow instructions and maintain the appointment schedule

Exclusion Criteria:

• has any systemic disease affecting ocular health and visual acuity
• is currently using any systemic or topical medications that could affect ocular health and visual acuity
• is participating in another eye related research study