Polymeric materials are actively used to upgrade existing optical devices in order to improve their physical and optical properties. High-tech and relatively cheap polymer optics is a means of solving technical problems related to reduction of assembly labor intensity, improvement of design and reliability of various optical systems. Currently, ophthalmology is the most advanced area for polymer technology development. The defining trend of improving spectacle optics is gradual replacement of lenses made of silicate glass with lenses made of polymer materials, the undoubted advantages of which are almost twice lower density and significant impact resistance. This work is devoted to the development of an optical system of telescopic glasses of small multiplicity, made by the scheme Galileo using modern optical polymers. The device is designed to improve the performance of the eye and can be used for medical operations. The calculation of the presented optical system is carried out by the Zemax program. The resulting optical system is characterized by high image quality, light weight and compactness.
In order to improve the eye performance, telescopic glasses with relatively small
magnification are used (Fig.1). Such systems have found wide application in
medicine, for manufacture of microelectronic schemes and jewels. The special requirement
at development of glasses is elimination of necessity for additional accommodation of
eyes at transition from observation with glasses and without them. This criterion is
achieved due to the location of the object and image in one plane [
To reduce the mass and dimensional characteristics, the calculation of telescopic
glasses optical system based on polymer lenses is proposed. Modern optical polymers
have high transparency and refractive power comparable to that of crown glasses. The
specific gravity of plastic is almost half that of glass, which allows the polymer lenses
to be much lighter. Currently, polymeric materials have many advantages over
mineral glass: low weight, injury safety, high impact resistance and low cost. Besides, today
the technologies of production and processing of optical polymers enable to create
complex surfaces (diffraction, aspherical, "freeform"), providing compensation of
aberrations and transformation of the beam shape [
Ophthalmology is the most common field of application of polymer optics as a means
of vision correction and eye protection. The main task of eyeglass optics is to ensure
completely natural vision for their wearer. The materials used in the manufacture of
corrective lenses must comply with a number of requirements [
Development of Telescopic Glasses Optical System Based on Polymer Lens 3 • chemical resistance to humid atmospheres; • low internal voltage; • easy to handle.
It should be noted that some of these requirements contradict each other and the material with the highest values for all these parameters has not yet been developed.
The fundamental characteristic of glasses is the refractive index n of material, as the thickness of the lenses directly depends on this value. The greater the refractive index, the finer optics can be manufactured. In addition, the value n also affects the optical power of the lens.
The optical properties of polymer materials for glasses lenses are commensurate with
those of traditional glasses. However, the level of light dispersion of polymers is
higher and can be manifested by coloring the contour of the object when viewed
through the peripheral areas. Nevertheless, as a rule, this defect is not fundamental for
most eyeglass wearers. In order to improve functional and operational characteristics
of polymer lenses, special coatings are used: to increase wear resistance of polymer
material, as a protection, etc. The polymeric materials are used for spherical and
aspherical lenses, astigmatic and astigmatic lenses, monofocal lenses, bifocal lenses and
lenses of various diameters (60-75 mm), which can be used for frames of any size [
Optical system of telescopic glasses is arranged according to Galileo's scheme that
does not require wrapping elements (Fig. 2).
The calculation principle for optical systems is based on the method of automatic
aberration correction. Initially, the system dimensional calculation is performed and
optimization parameters are formed. Then tracing rays in the initial scheme is realized
and, if necessary, optimization parameter limits are changed for the purpose of
reception for the best quality of the image and observance of design requirements. Table 2
shows the original characteristics of the optical system, which were determined based
on the design features. The magnification β of similar systems is in the 1.5 - 3ˣ, the
distance from the main plane of the first component to the plane of objects and images
a usually take from 300 to 400 mm. The distance between the main planes of the
components d is determined for structural reasons. As this parameter increases, the
relative diameters of the lenses are reduced, making it easier to correct aberrations.
However, as d rises, the total system size also becomes larger. The focal distances of
f'1 and f'2 components are determined using the basic formulas of geometric optics [
Development of Telescopic Glasses Optical System Based on Polymer Lens 5
The original glasses system includes positive and negative elements. To minimize
chromatic aberrations, optical materials should be selected so that the dispersion
coefficients are varied as much as possible. In addition, the Abbe value of the positive
component should be higher than that of the negative component [