Method and device for determining a contrast sensitivity threshold

A method for determining a contrast sensitivity threshold of eyes of a user, the method comprising:

• providing a dataset of track data, wherein the track data contains data of eye movements obtained by eliciting an optokinetic nystagmus in the eyes of the user by stimulating the eye movements with a stimulus, wherein the track data are related to a particular contrast and a particular spatial frequency of the stimulus;
• estimating at least one velocity component of the eye movement from the track data for the particular contrast and the particular spatial frequency of the stimulus;
• comparing the velocity component of the eye movement for the track data with a velocity threshold;
• determining the contrast sensitivity threshold of the eyes of the user;
• further comparing a fraction of the track data which exceeds the velocity threshold with a fractional threshold for the dataset, wherein the fraction of the track data which exceeds the fractional threshold is classified as eliciting the optokinetic nystagmus at the particular contrast of the stimulus, and
• wherein the contrast sensitivity threshold of the eyes of the user is determined by applying the velocity threshold and the fractional threshold,
• wherein the stimulus exerts a motion in at least one direction;
• presenting an optokinetic nystagmus (OKN) drum to the user;
• or
• presenting an image of a moving OKN drum to the user as virtual reality by providing at least one of a virtual reality headset, an augmented reality overlay, or a mobile communication device;
• wherein a different stimulus is used to exert the motion in a horizontal direction and in a vertical direction, respectively, and
• wherein the velocity component is estimated separately for a horizontal eye movement and a vertical eye movement, wherein the horizontal eye movement follows the motion of the stimulus in the horizontal direction, and wherein the vertical eye movement follows the motion of the stimulus in the vertical direction.

A method for determining a contrast sensitivity threshold of eyes of a user, the method comprising:

• providing a dataset of track data, wherein the track data contains data of eye movements obtained by eliciting an optokinetic nystagmus in the eyes of the user by stimulating the eye movements with a stimulus, wherein the track data are related to a particular contrast and a particular spatial frequency of the stimulus;
• estimating at least one velocity component of the eye movement from the track data for the particular contrast and the particular spatial frequency of the stimulus;
• comparing the velocity component of the eye movement for the track data with a velocity threshold;
• determining the contrast sensitivity threshold of the eyes of the user;
• further comparing a fraction of the track data which exceeds the velocity threshold with a fractional threshold for the dataset, wherein the fraction of the track data which exceeds the fractional threshold is classified as eliciting the optokinetic nystagmus at the particular contrast of the stimulus, and
• wherein the contrast sensitivity threshold of the eyes of the user is determined by applying the velocity threshold and the fractional threshold;
• and
• estimating the velocity threshold and the fractional threshold in a calibration process in which the contrast sensitivity is determined in a same manner with at least two different users, wherein same contrasts and same spatial frequencies of a same stimulus are utilized.

A non-transitory computer readable storage medium storing executable instructions for performing a method for determining a contrast sensitivity threshold of eyes of a user, the method comprising:

• providing a dataset of track data, wherein the track data contains data of eye movements obtained by eliciting an optokinetic nystagmus in the eyes of the user by stimulating the eye movements with a stimulus, wherein the track data are related to a particular contrast and a particular spatial frequency of the stimulus;
• estimating at least one velocity component of the eye movement from the track data for the particular contrast and the particular spatial frequency of the stimulus;
• comparing the velocity component of the eye movement for the track data with a velocity threshold;
• determining the contrast sensitivity threshold of the eyes of the user;
• and
• further comparing a fraction of the track data which exceed the velocity threshold with a fractional threshold for the dataset, wherein the fraction of the track data which exceeds the fractional threshold is classified as eliciting the optokinetic nystagmus at the particular contrast of the stimulus, and
• wherein the contrast sensitivity threshold of the eyes of the user is determined by applying the velocity threshold and the fractional threshold.

A device for determining a contrast sensitivity threshold of eyes of a user, the device comprising:

• a screen configured to display a stimulus, wherein the stimulus is designated for eliciting an optokinetic nystagmus in the eyes of the user;
• an eye tracker configured to record eye movements of the eyes of the user;
• and
• an evaluation unit, wherein the evaluation unit is configured to:
• provide a dataset of track data, wherein the track data contains data of the eye movements, wherein the eye movements are stimulated by a stimulus which is configured to elicit an optokinetic nystagmus in the eyes of the user, wherein the track data are related to a particular contrast and a particular spatial frequency of the stimulus;
• estimate at least one velocity component of the eye movement from the track data for the particular contrast and the particular spatial frequency of the stimulus;
• compare the velocity component of the eye movement for the track data with a velocity threshold;
• determine the contrast sensitivity threshold of the eyes of the user;
• and
• further compare a fraction of the track data which exceed the velocity threshold with a fractional threshold for the dataset, wherein the fraction of the track data which exceeds the fractional threshold is classified as eliciting the optokinetic nystagmus at the particular contrast of the stimulus, and
• wherein the contrast sensitivity threshold of the eyes of the user is determined by applying the velocity threshold and the fractional threshold.