Self-diagnosis within Arm's Reach

While the minimum predefined test distance is 2 meters, you may define a custom "arm's reach" distance, which should be at least 500 mm (50 cm or approximately 1.64 ft). After measuring the distance between your eyes and the hand or wrist holding the smartphone, enter this value under Custom Distance in Settings. Once saved, this distance will appear in the Predefined Distances list.

Remarks:

To detect symptoms of shortsightedness (myopia), the recommended test distance is at least 2 meters, which exceeds typical arm's reach. Since arm's reach is generally much shorter, this mode is suitable only for casual self-diagnosis—for example, when you're on a train. Please note that results obtained at shorter distances are inaccurate and unreliable. For better accuracy, consider using the Self-diagnosis with a Mirror mode.

Hints:

Some medical practitioners have found that the most practical test distance in hospital settings is around 1.2 meters. This corresponds to the typical length from a patient sitting upright in bed to the foot of the bed. Due to spatial constraints—such as curtain placement—it is often not feasible to test from farther away. Therefore, an arm's reach distance of 1.2 meters may be appropriate in such environments.