![]() ![]() The difference in direction and the ratio between the speed of the incident beam and that of its reflection can then be used to estimate the ocular refraction along this meridian. Moving the incident beam along a certain pupillary meridian (indicated by arrows in the figure) will result in a reflected beam that goes in the same or opposite direction as the incident beam. With ray tracing, the Tracey iTrace dynamically measures and analyzes wavefront aberrometry, or the focusing power of the human. ![]() We’re proud to continue developing iTrace capabilities as we stay at the leading edge of the vision industry, said Ray Sievert, Tracey’s executive vice president of Sales and Marketing. The operation of the iTrace may sound technical, but it operates on a straightforward premise. ![]() The device uses a single beam refractometer based on the retina for tracing and measuring the distribution of eye refraction. Tracey Technologies holds the patent to a highly advanced technology called ray tracing aberrometry. Tracey Technologies has released iTrace Prime, an upgraded software for the iTrace Ray Tracing Aberrometer and Corneal Topographer. The Tracey iTrace is a wavefront aberrometer designed by Tracey Technology. However, in a hyperopic eye the reflection is directed to the opposite side of the pupil. Practitioners use the aberration information provided by the Tracey devices to test and treat their patients vision. Because the retina can be considered a spherically concave mirror (reflecting about 4% of incident light), the beam is reflected back in more or less the original direction in a myopic eye. Wavefront Aberrometry is the dynamic measurement of the focusing power of the human eye, and the Tracey iTrace measures this by inputting parallel light. It uses focal shift in a different way, starting with the observation that the retinal image of a light beam coming from a superior direction is located below the optical axis in a myopic eye and above the optical axis in a hyperopic eye. The automatic retinoscope is an automated version of the handheld retinoscope and is implemented in an objective, serial, and double-pass fashion. The iTrace measures quality of vision and visual function using a fundamental thin beam principle of optical ray tracing, a first in eye care diagnostics. The uncomplicated nature of the technique makes it robust for extreme aberrations. The x-y scanner, comprising 2 separate scanners for the x- and y-directions, repeatedly moves the beam to a new entry position until homogeneously spread measurements are available for the whole pupil area. Using a beam splitter and lens, the retinal image is captured on a linear array of photodetectors and is made available for further processing. Once in the eye, local aberrations in the beam's entry position cause a focal shift of the retinal image with respect to a certain reference position. Ray tracing uses a narrow laser beam that is directed into the eye parallel to the eye's line of sight by means of an x-y scanner. The ray tracing principle is a serial, double-pass method using forward projection that can be implemented in both an objective and subjective manner. ![]()
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