Method and system for determining the refractive properties of an eye of a child

A system for determining the refractive properties of an eye, the system comprising:

• a wavefront measurement device for measuring the refractive properties of the eye,
• wherein the system is configured to have at least one measurement mode assigned to children,
• wherein the system has an input device configured to switch the system into said at least one measurement mode assigned to children, and
• wherein the system is further configured to alter at least one of the following defaults:
• a default pupillary distance, a default direction of a measurement ray of the wavefront measurement device and a default position of a forehead and chin rest assembly of the system, when the system is switched into said at least one measurement mode assigned to children;
• said system being further configured to adjust the measurement ray based on said defaults so as to cause said measurement ray to closely match the actual position of the eye;
• wherein the system further comprises an accommodation detection device and an alert device, wherein the accommodation detection device is a pupil size measurement device, and wherein the system is configured to provide an alert with the alert device in case an accommodation is detected by the accommodation detection device;
• and,
• wherein an accommodation of the pupil is detected and the alert provided by the alert device when a diameter of the pupil reduces its size below a threshold, wherein the threshold is set as 50% of a largest diameter of the pupil detected or as 70% of an initially detected diameter of the pupil.

A method for determining the refractive properties of an eye while avoiding accommodation thereof, the method comprising the steps of:

• providing a system including a wavefront measurement device for measuring the refractive properties of the eye;
• switching the system into one of at least one measurement mode assigned to children;
• altering a fixation target to the eye to avoid accommodation thereof, wherein the step of altering comprises showing the fixation target moving virtually from a first perceived distance from the eye to a second perceived distance therefrom during determination of the refractive properties of the eye, wherein the first perceived distance is less than the second perceived distance;
• determining the refractive properties of the eye with the system, wherein the method further comprises showing a video comprising the fixation target, wherein the video is a series of images shown with a frequency of at least 20 images per second;
• and,
• the first perceived distance being in a range from and including 1 diopters to and including 4 diopters, and the second perceived distance being in a range from and including 0.5 diopters to and including 0 diopters.

A method for determining the refractive properties of an eye, the method comprising the steps of:

• providing a system including a wavefront measurement device for measuring the refractive properties of the eye;
• switching the system into one of at least one measurement mode assigned to children;
• altering at least one of the following defaults:
• a default pupillary distance, a default direction of a measurement ray of the wavefront measurement device and a default position of a forehead and chin rest assembly of the system;
• adjusting the measurement ray based on said defaults so as to cause said measurement ray to closely match the actual position of the eye;
• determining the refractive properties of the eye with the system;
• wherein the system further comprises an accommodation detection device and an alert device, wherein the accommodation detection device is a pupil size measurement device, and wherein the system is configured to provide an alert with the alert device in case an accommodation is detected by the accommodation detection device;
• and,
• wherein an accommodation of the pupil is detected and the alert provided by the alert device when a diameter of the pupil reduces its size below a threshold, wherein the threshold is set as 50% of a largest diameter of the pupil detected or as 70% of an initially detected diameter of the pupil.

A method for determining a spectacle lens configuration for a child, the method comprising the steps of:

• determining the refractive properties of an eye with the following steps:
• providing a system including a wavefront measurement device for measuring the refractive properties of the eye;
• switching the system into one of at least one measurement mode assigned to children;
• altering at least one of the following defaults:
• a default pupillary distance, a default direction of a measurement ray of the wavefront measurement device, a default position of a forehead and chin rest assembly of the system and a fixation target;
• adjusting the measurement ray based on said defaults so as to cause said measurement ray to closely match the actual position of the eye;
• determining the refractive properties of the eye with the system;
• determining a refraction to correct an ametropia based on the determined refractive properties;
• determining a spectacle lens configuration based on the refraction;
• and,
• wherein the system further comprises an accommodation detection device and an alert device, wherein the accommodation detection device is a pupil size measurement device, and wherein the system is configured to provide an alert with the alert device in case an accommodation is detected by the accommodation detection device.