Lens: A piece of glass or other transparent material with one or more curved surfaces through which objects appear clear, larger, or smaller. Usually used in glasses, cameras, telescopes, etc
Classification: Lenses can be divided into the following five types according to different materials:
Resin lens special lens space lens glass lens PVC lens
The index of refraction refers to the refractive index of the lens, and the higher the index, the thinner the lens. Refractive index generally: 1.49, 1.56, 1.61, 1.67, 1.74.

Bifocal lens can be used to correct both far and near vision, mainly for presbyopia. The general distribution of bifocal lens is: the upper part of the lens is to see the distance, the lower part of the lens is used to watch the use of the near point, as for the size of the near norm, the nature of the near work to set.
Generally flat top dual lights are used most frequently, they only have a small area at the bottom of the lens for close-up work, while the periphery and top of the lens are used to look into the distance and provide a good peripheral view. Traditional double lens for a line of double light lens, the lens from the middle into two groups, which is less than half of the lens as nearly all point distance is used, they provide a good wide near point of view, for a long time in the near point workers has a better effect, architects, accountants, artists and other properties to  work, This kind of lens can reduce the chance that the head moves. The urn-shaped double light is more suitable for children and young students to use, which can not only meet the wide vision of looking at the close, but also meet the need of frequent rearview transformation of the far vision of looking at the blackboard. Bifocal lenses can also be used, but only for people who need to read orthotics in close proximity, but it is not easy to take the glasses on and off when working in close proximity.

BORIS OPTICAL is one of the most Potential Finished and Semi-Finished Optical Lenses factory located in Danyang City, China. It was establish in 2012 with covering 20000 spm and 150 employees. The annual production and sales of lenses are 30 million pieces, and the annual sales have exceeded 100 million for five consecutive years.
Our Key & Advantage Products:
Single Vision Lens:1.49;1.56;1.59;1.60;1.67;1.74
Bifocal Lens: 1.49; 1.56
Progressive Lens: CR-39; 1.56; 1.60
Functional Lens: Blue Cut, Photochromic; Photochromic +UV420 Blue cut; Sunglasses; Polarized; Polycarbonate
RX Service: Free Form; Special Coating; Special Power Range