SU145303A1 - The method of determining the position of the visual axis of the eye - Google Patents

Description

The known methods for determining the position of the visual axis, based on placing a certain foreign body on the eye surface or on measuring biopotentials resulting from natural polarization of the eye block, are complex and do not provide high accuracy, since they require either special preparation of the eye (anesthesia, , artificial wetting), or the use of complex equipment.

According to the proposed method, the cross pattern obtained on the screen of the cathode ray tube is projected onto the eye block under study, the light flux reflected from which is captured by a photomultiplier tube associated with the electron-tracking system. This permits the continuous determination of the position of the visual axis of the eye and simplifies the method.

The drawing shows a block diagram of an apparatus for carrying out the method.

The reference voltage generated by the master oscillator / lowers the sweep generator 2, the voltage from the output of which is applied to the deflection plates of the cathode ray tube 3, forming on its screen a cross pattern. The image obtained on the screen of the tube 5 with the help of object 4 is projected onto the fundus under study 5. Part of the light reflected from the fundus of the fundus. captured by a photomultiplier 6, associated with an electron-tracking system containing a resonant amplifier 7, phase detectors 5, 9, circuits} 0, and dynamic alignment. The reference voltages of the detectors 8, 9 are supplied from the master oscillator / through the matching phase shifters 12, 13, and obtained at the output of these. voltage detectors arrive at dynamic centering circuits. The direction of the alignment is chosen so that displacing the pupil of the eye relative to the cross causes it to shift in the same direction until the combined position is fully restored, the alignment accuracy being proportional to the gain of the electronically following system.