Ключевые слова: accessory, beam, black, collecting, collection, component, convex, device, dome, doubleconvex, educational, element, equipment, eyepiece, flatconvex, glass, hardware, hemisphere, industry, integral, item, kit, lens, light, magnifying, means, monocular, objects, optical, optics, parts, peak, pieces, pinnacle, refraction, refractive, scheme, science, semisphere, set, shine, spare, straightening, system, technology, top, transparent, upper, white,