Abstract: An eye alignment monitor and method are described for the detection of variability of the relative alignment of the two eyes with each other, thereby detecting deficits of binocular function, for use as a screening device for these abnormalities especially in infants and young children. Each embodiment includes means for tracking of the positions of a subject's two eyes simultaneously, and furthermore includes repetitive calculation of the relative positions of the two eyes with respect to each other. The embodiments do not require fixation by either eye on a specific point. Typically, a movie on a video display is used for viewing by the subject. Variability of relative alignment of the two eyes with each other is typically determined by variability of the relative positions of images of the pupils of the eyes with respect to each other over time.

Abstract: The present invention provides for very fast detection of gaze direction using retro-reflected light from the ocular fundus that is cost-efficient, small, and portable. These eye trackers are useful in many areas of science and technology, including but not limited to remote control, space, defense, medical and psycho-physiological applications, to identify for example subtle neurologic deficits that occur with cerebellar or vestibular disorders, Parkinson's disease, strokes, traumatic brain injury, possible concussions during sports matches, some forms of reading disability, or simply fatigue or inebriation. In ophthalmology, with two such devices operating simultaneously, the variability of relative eye alignment over time can be measured, without requiring individual calibration, and without requiring fixation on a specified target, ideal for use with small children.

Abstract: The present invention provides for very fast detection of gaze direction using retro-reflected light from the ocular fundus that is cost-efficient, small, and portable. These eye trackers are useful in many areas of science and technology, including but not limited to remote control, space, defense, medical and psycho-physiological applications, to identify for example subtle neurologic deficits that occur with cerebellar or vestibular disorders, Parkinson's disease, strokes, traumatic brain injury, possible concussions during sports matches, some forms of reading disability, or simply fatigue or inebriation. In ophthalmology, with two such devices operating simultaneously, the variability of relative eye alignment over time can be measured, without requiring individual calibration, and without requiring fixation on a specified target, ideal for use with small children.

Abstract: An eye tracking and gaze fixation detection system, includes an electronically scannable optical illumination system emits polarized near-infrared (NIR) light to a retina in an eye of a subject; an optical detection system arranged in an optical path of the NIR light after being reflected from the retina of the eye of the subject, the optical detection system providing a detection signal; and a signal processing system communicates with the optical detection system to receive the detection signal, wherein the optical illumination system emits the polarized NIR light to illuminate at least a portion of a scanning path, wherein the scanning path is a spatially closed loop across a portion of the retina in the eye of the subject that repeats periodically over time, and wherein the signal processing system is configured to determine at least one of a gaze direction and a gaze fixation based on the detection signal.

Abstract: The present invention provides apparatus and methods for detecting fixation of an eye of a subject on a target. The methods provide for optimization of parameters of the spinning half wave plate and the fixed wave plate in the retinal birefringence scanning (RBS) design to enable uses of the “spinning artifact” frequency component. Frequency of the “spinning artifact” component is determined by half wave plate rotation speed and direction. Amplitude is determined by interaction of the spinning half wave plate with any retardance encountered in the double-pass optics such as the fixed wave plate, corneal birefringence, and small amount of retinal birefringence. With optimum selection of fractional spinning frequency of the half wave plate, and the orientation/retardance of the fixed wave plate, the “spinning artifact” frequency component is essentially independent of fixation direction and is also essentially independent of the normal range of corneal birefringence.

Abstract: An eye alignment monitor and method are described for the detection of variability of the relative alignment of the two eyes with each other, thereby detecting deficits of binocular function, for use as a screening device for these abnormalities especially in infants and young children. Each embodiment includes means for tracking of the positions of a subject's two eyes simultaneously, and furthermore includes repetitive calculation of the relative positions of the two eyes with respect to each other. The embodiments do not require fixation by either eye on a specific point. Typically, a movie on a video display is used for viewing by the subject. Variability of relative alignment of the two eyes with each other is typically determined by variability of the relative positions of images of the pupils of the eyes with respect to each other over time.

Abstract: An eye tracking and gaze fixation detection system, includes an electronically scannable optical illumination system emits polarized near-infrared (NIR) light to a retina in an eye of a subject; an optical detection system arranged in an optical path of the NIR light after being reflected from the retina of the eye of the subject, the optical detection system providing a detection signal; and a signal processing system communicates with the optical detection system to receive the detection signal, wherein the optical illumination system emits the polarized NIR light to illuminate at least a portion of a scanning path, wherein the scanning path is a spatially closed loop across a portion of the retina in the eye of the subject that repeats periodically over time, and wherein the signal processing system is configured to determine at least one of a gaze direction and a gaze fixation based on the detection signal.

Abstract: The present invention provides apparatus and methods for detecting fixation of an eye of a subject on a target. The methods provide for optimization of parameters of the spinning half wave plate and the fixed wave plate in the retinal birefringence scanning (RBS) design to enable uses of the “spinning artifact” frequency component. Frequency of the “spinning artifact” component is determined by half wave plate rotation speed and direction, and amplitude is determined by interaction of the spinning half wave plate with any retardance encountered in the double-pass optics such as the fixed wave plate, the corneal birefringence, and the small amount of retinal birefringence. With optimum selection of the fractional spinning frequency of the half wave plate, and the orientation/retardance of the fixed wave plate, the “spinning artifact” frequency component is essentially independent of the fixation direction and is also essentially independent of the normal range of corneal birefringence.

Abstract: An eye fixation system for attention-attracting fixation of a user's eye includes an audio system configured to play sound based on audio signals to be audible to a user so as to attract the user's attention, and a target display system configured to communicate with the audio system to receive the audio signals and to display an optical target to be viewed by the user. The target display system includes an optical modulator configured to modulate the optical target based on the audio signals. A method of assisting a subject to fix at least one of his eyes in a predetermined alignment includes playing sound that is audible to the subject, displaying an optical target to be viewed by the subject synchronously with the sound such that the target is viewable by the subject while the sound is audible to the subject, and modulating the optical target based on the sound while the sound is being played.

Abstract: An apparatus for detecting fixation of at least one eye of a subject on a target includes an optical illumination system, an optical detection system, and a signal processing system adapted to communicate with the optical detection system. The signal processing system is configured to calculate at least one of a time-frequency distribution or an Auto-Regressive spectral estimation of the detection signal to provide a frequency distribution of the detection signal at a plurality of times for use in determining periods in which the subject's eye is fixed on the target based on the first and second frequency signatures.

Abstract: An apparatus for detecting fixation of at least one eye of a subject on a target includes an optical illumination system, an optical detection system, and a signal processing system adapted to communicate with the optical detection system. The signal processing system is configured to calculate at least one of a time-frequency distribution or an Auto-Regressive spectral estimation of the detection signal to provide a frequency distribution of the detection signal at a plurality of times for use in determining periods in which the subject's eye is fixed on the target based on the first and second frequency signatures.