Visual Acuity Charts 3.1.1

Designed with children aged 6 and above, parents of young children, and general practitioners in mind, this eye chart app provides accurate optotypes for measuring distance vision. It aims to assist in the early detection of myopia, encouraging proactive measures and timely consultation with medical professionals to prevent the progression from pseudomyopia to myopia or the worsening of nearsightedness.

Supported Eye Charts:

1. Snellen (C, D, E, F, H, K, N, P, R, U V and Z)
2. Tumbling E (with the option for a shorter middle arm)
3. Landolt C
4. ETDRS (C, D, H, K, N, O, R, S, V, and Z)
5. European-wide (H, K, O, E, P, X, B, T, M and A)
6. HOTV
7. Numbers
8. Shapes

Test Distances:

• Predefined distances: 6, 5, 4, 3 and 2 meters; 20, 15, 12, 10 and 6 feet
• Custom distance range: 0.5 - 30 meters or 1.6 - 98 feet

Scenarios:

1. "Doctor" and "Patient"
2. Self-diagnosis with a mirror using the mirror mode feature to stand at double the distance from the mirror with one eye covered and device screen facing the mirror
3. Self-diagnosis with a Bluetooth keyboard from a few meters away by using the keyboard's direction keys to indicate readings

Notations:

• Decimal (0.50)
• Fraction (20/40)
• LogMAR (0.30)
• Fraction (5/10)
• Fraction (6/12)
• MAR (2)
• VAS or VAR (85)

Test Modes:

1. Manual
2. Auto scoring: Utilize swiping gestures to indicate correct or wrong readings for automated scoring and progress tracking by enabling "Record Scores" in settings

The study "Visual Acuity Testing for Telehealth Using Mobile Applications" published in JAMA Ophthalmology noted that Visual Acuity Charts are ranked as the most accurate among ten tested apps on iPhones.

Initial screening for myopia often involves testing distant visual acuity with visual acuity charts as decreased visual acuity may suggest myopia development.

Disclaimer:

This app offers a digital alternative to traditional printed eye charts but is not a substitute for in-depth eye examinations conducted by healthcare professionals like doctors and optometrists. Conditions like strabismus, esotropia, exotropia, hyperopia, and astigmatism are not tested by this app despite being common early vision issues. Regular visits to optometrists are advised upon noticing early signs of visual acuity problems.