Systems and methods for evaluating contrast sensitivity function

A system for assessing a contrast sensitivity function of a person, comprising:

• a display;
• an eye-tracking device configured to detect the gaze position of one or both eyes of the person;
• a non-transitory memory having a machine-readable medium comprising machine executable code;
• and
• one or more processors coupled to the non-transitory memory, said one or more processors configured to execute the machine executable code, causing the one or more processors to:
• a) generate an ordered sequence of a set of one or more visual stimuli vectored from a common origin on the display, the visual stimuli comprising both contrast and spatial frequency components;
• b) present at a first area of the display a first image;
• c) receive from the eye-tracking device data indicating a second area of the display to which the person's gaze is directed;
• d) pre-calibrate the eye-tracking device based on the location of the first area and the location of the second area;
• e) store in the non-transitory memory a software algorithm that sets a path for each of the visual stimuli of the set to follow on the display;
• f) store in the non-transitory memory an evidence-of-visibility score and one or more predetermined modification values;
• g) present on the display a first visual stimulus of the set of one or more visual stimuli, wherein the first visual stimulus moves in a path on the display as set by the software algorithm for a first period of time;
• h) receive from the eye-tracking device first data indicating a gaze position and an eye position of one or both eyes of the person for the first period of time;
• i) use the first data to determine whether the gaze position and eye position of one or both eyes of the person during the first period of time are directed to the position on the display of the first visual stimulus during the first period of time;
• j) select a predetermined modification value based on whether the gaze position and eye position of one or both eyes of the person during the first period of time are directed to the position on the display of the first visual stimulus during the first period of time;
• k) increase or decrease the evidence-of-visibility score by the predetermined modification value;
• l) changing, when the evidence-of-visibility score resulting in k) is above a predetermined threshold value indicating that the person can see the first visual stimulus, the contrast and changing the spatial frequency of the first visual stimulus so as to generate a second visual stimulus;
• m) reiterating steps g) through l), except when in step l) the evidence-of-visibility resulting from k) is below a predetermined threshold value, thus indicating that the person can no longer see the visual stimulus, and thus identifying one point of the contrast sensitivity function, and
• n) repeating step m) for each visual stimulus until a predetermined number of points of the contrast sensitivity function have been obtained,
• so as to determine a contrast sensitivity function of the person.

A method for assessing a contrast sensitivity function of a person, comprising:

• i) generating one or more sequences of one or more visual stimuli both contrast and spatial frequency components;
• ii) pre-calibrating an eye-tracking device based on the person's gaze;
• iii) determining, using an algorithm, a path for each of the visual stimuli of the one or more sequences to follow on a display wherein the visual stimuli are vectored from a common origin;
• iv) presenting on the display during a first period of time a first visual stimulus of a first of the one or more sequences of visual stimuli, wherein the first visual stimulus moves on the display along a first path determined by the algorithm for the first visual stimulus;
• v) receiving, from an eye-tracking device, one or more gaze position signals and one or more eye position signals detected from one or both eyes of the person as the first visual stimulus moves along the first path on the display;
• vi) calculating a first evidence-of-visibility score for the first visual stimulus by comparing the one or more gaze position signals and one or more eye position signals to one or more locations of the first visual stimulus on the display during the first period of time;
• vii) modifying, based upon the first evidence-of-visibility score, the contrast and the spatial frequency of the first visual stimulus;
• viii) calibrating the eye-tracking device based on the evidence-of-visibility score;
• ix) reiterating steps iv) through vii) until the evidence of visibility score calculated in vi) falls below a predetermined threshold value, thus indicating that the subject can no longer see the first visual stimulus, thereby identifying one point of the contrast sensitivity function, and
• x) repeating step ix) for each visual stimulus of the one or more sequences until a predetermined number of points of the contrast sensitivity function have been obtained,
• so as to determine a contrast sensitivity function of the person.