What vision screeners make money on

Vision health care products. According to the query surging news network shows that the development of vision health care products are eye drops, eye patches, eye film, etc., rely on the sale of vision health care products to obtain income. Vision screening instrument is the use of light through the eye's refractive system focus refraction to the receptors, after processing to derive the two eyes of the sphere diameter, column diameter and axial position and other refractive data of an instrument.