This app displays optically accurate optotypes of eye charts on smart phones and tablets. At exactly 6 meters away from the “patient”, the optotypes on the 6/6 line (Decimal 1.0 or LogMar 0.0) shall subtend 5 minutes of arc, which means that the chart should be sized such that these optotypes are 8.73mm tall, and the topmost (Snellen Fraction 6/60, Decimal 0.1, or LogMar 1.0) optotypes should be 87.3 mm tall. At exactly 20 feet away from the “patient”, the topmost optotypes should be 88.7 mm tall, because 20 feet equals 6.096 meters. Therefore, this app enables you as a home user or health professional to detect and measure visual acuity, particularly nearsightedness or myopia.
Supported Eye Charts:
1. Snellen Chart, with C, D, E, F, H, K, N, P, R, U V and Z, as defined in BS 4274-1:2003
2. Tumbling E Chart
3. Landolt C Chart
4. ETDRS Chart, with C, D, H, K, N, O, R, S, V, and Z
5. HOTV Chart
6. ETDRS European-wide Chart, with H, K, O, E, P, X, B, T, M and A
7. LEA Symbols for preschool-age children
8. LEA Numbers
1. "Doctor" and "Patient".
2. Self-diagnosis with a mirror.
3. Self-diagnosis within arm's reach
Predefined Test Distances:
* 6, 5, 4, 3, and 2 meters
* 20, 15, 12, 10, 6 feet
And an arm's reach distance may be defined in Settings.
Last updated 4 Jan 2019