Vision test apparatus, method and system and non-transient computer readable recording medium

A vision test apparatus comprising:

• a hollow housing made of translucent or transparent materials, wherein the hollow housing is configured to allow external ambient light to pass therethrough to illuminate a test optotype when the vision test apparatus is attached to an external display apparatus;
• a converging lens arranged in the hollow housing, and comprising a converging focal length;
• a diverging lens arranged in the hollow housing at intervals relative to the converging lens, and comprising a diverging focal length;
• two optical axes of the diverging lens and the converging lens configured to overlap each other, and the diverging focal length configured to partially overlap the converging focal length, wherein a magnification of the converging lens and the diverging lens is between 10 and 15, a length of the vision test apparatus is between 190 mm and 130 mm, thereby a range of tested visual acuity levels of the vision test apparatus is increased and an effect of the tested visual acuity levels is improved;
• a diaphragm arranged in the hollow housing between the converging lens and the diverging lens, and adjacent to the converging lens, wherein the diaphragm is configured to filter out an excess scattered or refracted light generated between the converging lens and the diverging lens;
• and
• a light shield connected to one end of the hollow housing, and adjacent to the diverging lens, the light shield comprising a tapered structure and tapered toward the diverging lens, wherein the light shield is configured to be attached to the external display apparatus, and wherein the light shield is used to eliminate reflected or refracted lights and to maintain a fixed distance between the diverging lens and the display screen of the external display apparatus;
• wherein, one end of the hollow housing adjacent to the diverging lens is configured to receive a test optotype displayed by the external display apparatus, the diverging lens is configured to demagnify the test optotype to form a first virtual image within the converging focal length, and the converging lens is configured to magnify the first virtual image to form a second virtual image for a vision testing;
• wherein, a periphery of an opening at one end of the light shield comprises any one of a silicone layer, an electrostatic glass sticker, and a chemical adhesive layer;
• wherein, the first virtual image is located at the overlap of the converging focal length and the diverging focal length.