The Principle Of Optometry Instrument

Optometry Instrument is an objective optometry equipment, which is the product of the combination of refractive inspection technology and computer technology. Measurement without the subjective judgment of clinicians and subjects, the objective evaluation of refractive parameters by predetermined criteria. Because the computer optometry is simple, fast, and the learning cycle is short, Optometry Instruments it is suitable for quick access to objective diopter and as a starting point for primary optometry or for routine eye care screening. With the application of high technology in optometry instrument, the accuracy of optometry instrument has been improved greatly, many instruments integrate the function of corneal curvature meter or corneal topographic map, Optometry Instruments and the instruments of some manufacturers are automatically online with comprehensive optometry instrument, and the measurement results are directly imported into the comprehensive optometry instrument, which is convenient to use Portable optometry instruments can also be used during surgery and screening.

The principle of optometry instrument

The design principles of most optometry instruments are based on indirect fundus mirrors, using two objective lenses or focus mirrors and a splitter, the light source is directly entered by the pupil edge, the detection cursor can be moved along the axis of the projection system, the projecting lens in the front focal plane, Optometry Instruments and its image will be in infinity, then focus on the retina of the eye squarely. If the detected eye is refractive, the detection cursor moves back and forth, making it like focusing on the retina, most of the optometry instrument is to make the cursor clearly imaging on the retina and automatically calculate the diopter of the eye by changing the degree of light that enters the eye.

The design of optometry instruments usually has two main features:

Regulation control is especially important for most optometry methods. Almost all optometry requires the person to gaze at the test cursor or cursor image, the results stimulated the adjustment and made the test results myopic or hyperopia, although the test cursor was designed in infinity by the optical path, Optometry Instruments the proximity of the instrument to the face of the seized person evoked a near-perceptual adjustment, so the cursor was tested in the design process. Fog visualization ", before the beginning of the measurement, the subject saw a" fog "cursor to relax the adjustment, but could not completely remove the near-perceptual adjustment. 2. Optometry Instruments Detection of light for infrared light is currently used by the optometry instrument detection of light using wavelength of 800~ $number nm infrared light. The reason is: ① infrared is absorbed in the eye less than visible light, reflected by the fundus more light. Therefore, it is more important to detect the light energy loss after the light has passed through the intraocular medium, especially the eyes with cloudy refractive media. ② for the eyes, the detection of visual standard and detection of light is not visible, better to overcome the measurement of the problem of adjustment caused by the visual standard. Due to the different production companies, the design and structure of optometry instruments are also different, and the inspectors need to read the instructions in detail before using optometry instruments. The common structure of optometry instrument is: ① the cursor that the inspector stares at. ② Optometry Instruments can adjust the jaw and head to make the patient's head position fixed during the examination. ③ joystick can be moved back and forth, up and down, to focus and adjust the position of the eye of the seized person. The ④ monitor displays the location and measurement results of the inspected eye. ⑤ printing device.