Nowadays, customers of optical salons have become more informed and make more demands on the quality of the glasses they make. It is difficult for optical workshops that do not have a proper production base to compete with large companies that are actively introducing modern lenses and frames into their work. The use of new automation technologies allows you to almost completely abandon the intermediate operations and manual labor in the process of making glasses. This significantly increases the competitiveness of products. Modern automatic equipment is easy to operate and provides high quality processing of lenses from a wide variety of materials, including modern ones. Therefore, now this type of equipment is becoming more and more widespread.

The automatic lines include a scanning device, a centering device and a machine for processing spectacle lenses along the contour. Scanners are designed to obtain accurate information about the shape and dimensions of the rim opening in frames of any type. On the centralizers, the lens is centered and blocked. On machines, lenses are processed along the contour with the application of any type of facet. Various automatic lines are produced that differ in the accuracy of scanning frames, the principles of centering spectacle lenses and the ability to perform additional operations, such as chamfering, drilling, milling, etc. Modern automatic machines for processing spectacle lenses have a very wide range of technical capabilities.

The shadow test method (skiascopy) to determine the refraction of the eye is an important ophthalmological test that allows you to diagnose the type of refraction of the eye, carry out differential diagnosis and determine the severity of various pathologies, such as astigmatism, myopia or hyperopia.

A skiascopic ruler is used for diagnostics. This measuring device consists of two linear frames, in one of which plus lenses are inserted in succession increasing in optical power, and in the second - minus lenses in the range. Some ruler models have an additional lens attachment to reduce the pitch or increase the range.

The essence of the method is to observe the movement of shadows in the pupil area under the influence of a beam of light reflected from an ophthalmic mirror. By moving the mirror at different angles, the researcher obtains a moving shadow, clearly visible on the illuminated pupil. Having found the position of the shadow with the help of a skiascopic ruler, the refraction of the eye is determined.

To obtain reliable diagnostic data, technology and a clear sequence of all stages of the procedure, the quality of the equipment used are important, and therefore, it makes sense to choose the lines of reputable manufacturers. In addition, when choosing, the range of available refraction measurements, the width and length of the ruler, and the quality of the moving mechanism of the frame are taken into account.

The main advantages of the shadow test method are painlessness and objectivity, due to which skiascopic rulers are suitable for determining refraction in children, people with low intelligence, and simulant patients.