Prevention is better than cure. Designed for children older than 6, parents with young children, and general practitioners, this app displays optically precise optotypes of Snellen Chart for you to measure distant visual acuity accurately in order to detect nearsightedness or myopia and early, so you can take preventive measures and seek help from medical professional early to prevent pseudomyopia from becoming myopia, or prevent nearsightedness from getting worse. Predefined Test Distances: *