The Working Principle Of LCD Vision Meter

LCD vision meter, also known as automatic electronic vision tester, as the standard arrangement in line with the new national vision standards. The liquid crystal vision table for children, adolescents or automatic electronic vision examination of the general physical examination, visual barrier screening and ophthalmology and optometry clinical diagnosis and treatment, academic, scientific research, teaching and audition and other aspects of vision determination. LCD Visual Acuity Chart Especially for the air force recruitment examination of visual inspection, to solve the medical staff command, evaluation, recording, statistics and other work on the results of the results, so that the results more just and reasonable.

Automatic electronic LCD vision meter set of precision, convenience, versatility and other advantages in one of the automatic anti-cheating LCD visual acuity chart. Simple operation process: select the test items - credit card - ready - detection - automatic report - the results of printing - storage. The whole process without medical personnel command, greatly reduce the workload of medical staff

The LCD vision meter is a chart for measuring vision. Domestic use of LCD visual acuity tables are: international standard LCD visual acuity chart, LCD visual acuity logarithmic LCD visual acuity chart, blue (Landolt) ring LCD vision meter. From the function points on the near liquid crystal vision table, far liquid crystal vision table. LCD vision meter is based on the principle of perspective to develop. Examination of vision is generally divided into two categories of distant vision and near vision, far vision more use of international standard LCD vision meter, the table for the 12 different sizes of different openings in the direction of the "E" word composition; measured from 0.1-1.5 (or from 4.0-5.2); each line has a label, the subject of the visual line as the visual line to operate with the 1.0 line parallel to the line from the LCD visual acuity of 5 meters, the LCD vision meter and the distance to be checked must be properly fixed, Table for 5 meters.

1 Introduction

The LCD vision meter is a chart for measuring vision. Domestic use of the LCD visual acuity tables are: the international standard LCD visual acuity chart, the number of liquid crystal visual acuity chart, Lan (Landolt) ring LCD vision meter

The From the function points on the near liquid crystal vision table, far liquid crystal vision table. LCD vision meter is based on the principle of perspective to develop.

2 use

The current use of LCD vision meter is the main examination of the central vision, that is, LCD Visual Acuity Chart check the retina macular fovea visual acuity, which can be simple and easy to understand the initial visual function of the clinical diagnosis and treatment of eye disease are of great significance.

3 working principle

LCD vision meter is based on the principle of perspective design. LCD Visual Acuity Chart The so-called perspective is the light emitted by the outside two points, the angle formed by the intraocular nodes (that is, outside the object of two points into the eye when the intersection of the introduction of the angle). Under normal circumstances, the human eye can distinguish between the two points between the minimum distance formed by the perspective of the minimum perspective, that is, a sub-angle. LCD vision meter is a sub-angle as a unit for the design of effective detection of vision from the.

Method of operation

Check the visual acuity is generally divided into two categories of distant vision and near vision, in our country mainly use the standard logarithmic LCD visual acuity chart, (in May 2012 implementation of the second generation), this table for the 12 lines of different openings in different directions " E "; measured from 0.1-1.5 (or from 4.0-5.2); each line has a label, the subject's

Line to parallel with the line of 1.0, 5 meters away from the LCD vision meter, LCD vision meter and the distance to be checked must be properly fixed, the patient from the table for 5 meters. If the indoor distance is not 5 meters long, you should place a plane mirror at 2.5 meters to reflect the LCD vision meter. To detect the first cover one, monocular from top to bottom to identify the "E" word gap direction, until it can not be identified so far, you can record it. Normal vision should be above 1.0. If the test can not see 0.1, to move forward until you can see 0.1, its vision is "0.1 × distance / 5 = vision"; if within half a meter still can not see 0.1, can be made Testers identify the index, measured manual, light perception and so on. Record the vision according to the inspection. Near vision can use the "J" near the LCD vision meter, the same way to identify the "E" word gap direction, until it can not be identified so far, LCD Visual Acuity Chart close to self-adjustment, normal near vision at 30 cm to see 1.0 line can be, near vision test Help the diagnosis of refractive errors.