Error-eliminating double-cylindrical-mirror astigmatism-correcting device and subjective and objective optometry unit

Abstract

The invention discloses an error-eliminating double-cylindrical-mirror astigmatism-correcting device and a subjective and objective optometry unit and relates to an ophthalmology optometry device for high-precision subjective and objective examination. In the error-eliminating double-cylindrical-mirror astigmatism-correcting device, two cylindrical mirrors are placed on a focal plane of a 4f system composed of two convex lenses respectively. Astigmatism is corrected through rotation of the two cylindrical mirrors along an optical axis; and a main optical path and two branch optical paths for subjective and objective optometry are reasonably arranged by the optometry unit. The optometry unit has advantages that an image judgment device for three-dimensional positioning of eyes and objective and subjective diopter measurements are combined into the optometry unit, a technical problem that the two cylindrical mirrors are arranged on a conjugate surface at the same time to eliminate errors is solved through a two-pupil equivalent conjugate surface structure, and diopter measurement is rapid and correction is accurate. A communication design of the main optical path and the two branch optical paths is reasonable, channel paths of the branch optical paths are short, and due to the fact that errors generated by the branch optical paths are small, objective and subjective measurement results obtained by the optometry unit are more accurate.

Description

technical field [0001] The invention relates to the technical field of optical measurement used in ophthalmology, in particular to a high-precision optometry device for subjective and objective measurement. Background technique [0002] At present, the commonly used clinical refractometer mainly includes combined lenses and eye charts. When people carry out optometry, the routine process is to first obtain the diopters of the left and right eyes through ophthalmoscope or objective refractometer, and then use the comprehensive refractometer according to the measurement. The obtained diopter of the patient is simulated to wear, and the optometrist issues an adjustment command to correct the simulated wearing degree until the correction is the best for the patient's subjective experience. [0003] Chinese patent CN201610303646.6 introduces an optometry method of a comprehensive refractometer. The patient's diopter needs to be measured in advance on an objective refractometer, a...

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Problems solved by technology

[0003] Chinese patent CN201610303646.6 introduces an optometry method of a comprehensive refractometer. The patient's diopter needs to be measured in advance on an objective refractometer, and then moved to the comprehensive refractometer, and the combined lens generates the corresponding degree to complete the comprehensive optometry. In this optometry process, objective optometry obtains continuous refractive errors, but subjective optometry can only select test lenses step by step, and the differences between them affect the accuracy of optometry; and astigmatism lenses have directionality, and their angle tolerance is small, and operation is difficult. The angle error will affect the accuracy of optometry when inserting the film manually

However, in this patent, there are two separated but overlapping cylindrical mirrors near the position conjugated to the pupil of the tested human eye. Since the cylindrical mirrors have thickness, the two cylindrical mirrors Can not be in the position of the same conjugate surface at the same time, no matter one cylindrical mirror is in the position of the conjugate surface, the other cylindrical mirror is not in the position of the conjugate surface, or the two cylindrical mirrors are respectively located on the two sides of the conjugate surface On the technical side, there is a technical defect that the two cylindrical mirrors cannot be at the position of the pupil conjugate plane at the same time. As a result, there is an error between the synthetic astigmatism produced by the two cylindrical mirrors and the astigmatism that needs to be corrected. The larger the astigmatism value The greater the error

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