Eye Charts

Fonlow

About this app

Designed for children over the age of 6, parents with young children, and general practitioners, this eye chart app displays optically precise optotypes for accurate distance vision measurement. Early detection of myopia allows you to take preventive action, seek medical advice promptly, and prevent pseudomyopia from worsening into myopia or stop nearsightedness from deteriorating further.

Supported Eye Charts:
1. Snellen, with C, D, E, F, H, K, N, P, R, U V and Z, as defined in BS 4274-1:2003.
2. Tumbling E. Option to have shorter middle arm.
3. Landolt C.
4. ETDRS, with C, D, H, K, N, O, R, S, V, and Z.
5. ETDRS European-wide, with H, K, O, E, P, X, B, T, M and A.
6. HOTV.
7. Numbers.
8. Shapes.

Test Distances:
* 6, 5, 4, 3, and 2 meters predefined
* 20, 15, 12, 10, 6 feet predefined
* Custom distance 0.5 - 30 meters, or 1.6 - 98 feet.

Scenarios:
1. Doctor and Patient.
2. Self-diagnosis using a mirror – Stand in front of a mirror with the app in mirror mode, wearing an eye patch over one eye. The effective test distance is twice the distance between you and the mirror.
3. Self-diagnosis using a Bluetooth keyboard – Place the device a few meters away on a table, and use the keyboard arrow keys to indicate what you can read.

Notations：
1. Decimal (0.50)
2. Fraction (20/40)
3. LogMAR (0.30) with LogMAR scoring
4. Fraction (5/10)
5. Fraction (6/12)
6. MAR (2) with LogMAR scoring
7. VAS or VAR (85) with LogMAR scoring

Test Modes:
1. Manual.
2. Auto scoring – Swipe gestures indicate correct or incorrect readings, and the app calculates scores. Enable "Record Scores" in Settings to track visual acuity progression, with support for multiple test subjects.

According to “Visual Acuity Testing for Telehealth Using Mobile Applications,” published in JAMA Ophthalmology on https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7809609/, this app (formerly known as Visual Acuity Charts) demonstrated the highest accuracy among 10 iPhone-based visual acuity chart applications.

Myopia detection involves several steps, with distance visual acuity testing often being the first. A decline in visual acuity may indicate the onset of myopia, enabling early intervention.

Disclaimer:
While this app may replace printed eye charts, it CANNOT replace doctors or optometrists who perform comprehensive eye exams essential for maintaining eye health. The app does not test for strabismus, esotropia, exotropia, hyperopia, or astigmatism—common early vision conditions. Please consult an optometrist regularly and seek professional medical advice at the first signs of visual acuity issues.

Ratings and reviews

Fairly accurate as I had measured the size of optotypes with a ruler. And the brightness of the app could be independent of my phone's brightness setting since I generally keep low brightness, while testing from a distantce requires brighter background.

works on my S23 Ultra (worst phone I've ever owned).

Handy to use to check up visual every now and then

What’s new

1. Most built-in help contents are refined.
2. When the visual acuity notation is LogMAR, MAR or VAS, the scoring of the assessment is LogMAR Scoring.