VisionApp - Refraction and Presbyopia

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 refraction and presbyopia. 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).

Inclusion Criteria: * at least 40 years of age and currently wears a near add correction * has a refractive error between Plano and -5.00 D of sphere and cylinder components combined. * has best corrected visual acuity of at least 20/20 in each eye * is not amblyopic or 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