Visual Acuity Charts

4.5
75 reviews
10K+
Downloads
Content rating
Everyone
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About this app

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 eye charts for you to measure distant visual acuity accurately in order to detect nearsightedness or myopia 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.

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. Option to have shorter middle arm.
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. Numbers

Predefined Test Distances:
* 6, 5, 4, 3, and 2 meters
* 20, 15, 12, 10, 6 feet

Scenarios:
1. "Doctor" and "Patient".
2. Self-diagnosis with a mirror. With one eye covered by an eye patch and holding the device near the shoulder, you stand in front of a typical bathroom mirror using the mirror mode of the app and having the device's screen facing the mirror. The actual test distance is 2 times of the distance between you and the mirror.
3. Self-diagnosis with a Bluetooth keyboard. After putting the device standing a few meters away on a table, you use the keyboard's direction keys to indicate what your read.
4. Self-diagnosis within arm's reach.

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

Test Modes:
1. Manual.
2. Auto scoring

In Auto scoring, you use the swiping gestures to indicate correct readings or wrong readings, and the app calculates the score. For LogMAR notation, the score is (LogMAR value of the best line read) + 0.02 x (number of optotypes missed). And the maximum missed is 3. For VAS notation, the score is an inversion of the logMAR scale, based on VAS=100-50xlogMAR. For other notations, the score is the notation value of the best line read and optionally minus number of optotypes missed, and the maximum missed is 2.

By default, setting "Play Interval Until Next Optotype" is none. Available intervals in second includes: 2, 4, 6, 8, and 10. If the "patient" could not recognize the optotype within the interval, this counts a miss.

Through enabling “Record Scores” in Settings, you can keep track of the progression of your visual acuity. Visual acuity scores of multiple testees could be recorded.

Visual Acuity Score (VAS) is an inversion of the logMAR scale, based on VAS=100-50xlogMAR. It is more intuitive since higher values indicate better visual acuity.

In the scores review, score 100 in blue indicates the reference standard, scores above 100 in green indicates no myopia, while scores below 100 in red may indicate myopia.

You may copy the scores of current patient to the device's clipboard, then you may paste the scores to a drafted Email message or instant message. This may be handy for telemedicine / telehealth session when the medical practitioner asks for VA scores.

Testing for myopia takes several procedures and the first step is often to check distant visual acuity through a visual acuity chart. And the decrement of visual acuity may indicate the development of myopia.

Disclaimer:
While this app may replace eye charts in print, however it cannot replace doctors and optometrists who carry out comprehensive tests for your eyes. Please visit optometrists regularly and seek help from medical professional at early signs of visual acuity problems.
Updated on
Oct 29, 2021

Data safety

Safety starts with understanding how developers collect and share your data. Data privacy and security practices may vary based on your use, region, and age. The developer provided this information and may update it over time.
No data shared with third parties
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No data collected
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4.5
75 reviews
ali Meneses
November 13, 2020
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.
16 people found this review helpful
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Josh O'Niell
December 28, 2021
Handy to use to check up visual every now and then
1 person found this review helpful
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José A. Aponte
April 27, 2021
"260421..kfr..thank's..."
4 people found this review helpful
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What's new

1. Setting for displaying multiple optotypes of current row.
2. When multiple optotypes are enabled in current row, wipe left or right or press the Next button to shuffle optotypes.
3. In Auto Scoring mode, the testee should read the central optotype.