Method and system for evaluating visual acuity of a person
A method for evaluating the visual acuity of a person using a mobile device having at least a front camera and a screen, the method including a user positioning step during which the user of a mobile device positions himself in front of a mirror at a predefined distance d/2, a mobile device positioning step during which the mobile device is positioned with the front camera of the mobile device facing the mirror, a distance measuring step during which a distance d between the front camera of the mobile device and a virtual image of the mobile device in the mirror is measured, a displaying step during which the screen of the mobile device displays optotypes, and an evaluation step during which the visual acuity of the user is evaluated.
1 . A method for evaluating a visual acuity of a person using a mobile device having at least a front camera and a screen, the method comprising:
positioning a user of a mobile device in front of a mirror at a predefined distance d/2,
positioning the mobile device with the front camera of the mobile device facing the mirror;
measuring a distance d between the front camera of the mobile device and a virtual image of the mobile device in the mirror;
displaying optotypes on the screen of the mobile device;
receiving an indication from the user in response to the displayed optotype;
evaluating, using processing circuitry, the visual acuity of the user, based on the received indication from the user; and
receiving mobile device data, the mobile device data including at least screen data relating at least to a physical size of the screen of the mobile device and camera data relating at least to an angular resolution of a front camera's pixel,
wherein the distance d is measured based at least on the mobile device data,
wherein the distance d/2 between the front camera and the mirror is regularly measured during the displaying and the evaluating, and
wherein the size and/or angular size of the optotypes displayed during the displaying is adapted in real-time based on the measured distance d/2.
2 . The method according to claim 1 , further comprising, prior to the displaying, comparing the measured distance d to the predefined distance d/2.
3 . The method according to claim 2 , further comprising sending a notification to the user based on comparison of the measured distance d and the predefined distance d/2.
4 . The method according to claim 1 , wherein a size and/or angular size of the optotypes displayed during the displaying is adapted based on the measured distance d.
5 . The method according to claim 1 , wherein the optotypes displayed on the screen of the mobile device during the displaying includes a single Landolt-C with varying directions, and
wherein the indication received from the user relates to a direction of an aperture of the Landolt-C perceived by the user.
6 . The method according to claim 5 , wherein the perceived direction of the Landolt-C aperture is indicated by the user using speech recognition and/or gesture recognition and/or movement of the mobile device.
7 . The method according to claim 5 , wherein the displayed optotype further includes a movable cursor and the perceived direction of the Landolt-C on the screen of the mobile device is indicated by a position of the movable cursor.
8 . The method according to claim 7 , wherein the mobile device includes physical plus and minus volume buttons, and
wherein the movable cursor is controlled by the user using the physical plus and minus volume buttons of the mobile device.
9 . The method according to claim 1 , wherein the mobile device is holdable with a single hand.