Method for drawing standard naked-eye E chart

Abstract

The invention discloses a method for drawing a standard naked-eye E chart. The method comprises following steps of step 1, acquiring pixel point data occupied by a reference standard card on a display through the display of a computer equipped with the eyesight screening software; step 2, calculating to acquire the actual side length of the E chart; step 3, comparing the actual width of an identity card with the actual side length of the E chart to acquire the actual ratio of the E characters; step 4, comparing the pixel width corresponding to the identity card with the actual ratio of the E characters to acquire side length pixels of the E characters; step 5, carrying out pixel side length restriction on an E character vector graph (which is square) drawn in the system; and step 6, displaying images of the E characters. According to the invention, the size of the standard naked-eye E chart is drawn based on the actual object size and computer displays with different resolutions; the size of the standard naked-eye E chart can be equivalently scaled according to the distance value; consistent effects with actual eyesight measurement data are achieved; and accuracy and reliability of the eyesight measurement data are ensured.

Description

technical field [0001] The invention relates to the technical field of naked-eye vision screening, in particular to a method for drawing a standard naked-eye vision chart E. Background technique [0002] At present, naked-eye vision screening activities in the market are all based on the general inspection of naked-eye vision chart light boxes. To check vision, you need to prepare standard logarithmic vision chart light boxes, optotype indicator sticks, eye-shielding spoons and other inspection equipment. During the inspection, the eye chart light box is hung on the wall. The height of the 1.0 line of the eye chart is at the same height as the eye being inspected. The distance from the surface of the light box eye chart to the surface of the eyeball of the examinee is 5 meters or 2.5 meters Every 1 meter, 2 meters, 3 meters, 4 meters and 5 meters away from the surface of the light box should be marked. The light of the eye chart light box should be easy to use, the surface ...

AI Technical Summary

Problems solved by technology

[0003] However, there are many defects in the above-mentioned current existing technologies. First, the size of the vision screening light box is problematic. Due to the site, the front-line personnel need to carry multiple naked-eye eye charts with standard distances. Secondly, the accuracy and reliability of the detection data are poor. and labor-intensive

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