• Product Name
  • Product Keyword
  • Product Model
  • Product Summary
  • Product Description
  • Multi Field Search
Clear CR39 1.499 Round-Top Uncoated Prescription Eyeglass Lenses For Optical Usage
Home » Products » Index 1.499 Lens » Clear CR39 1.499 Round-Top Uncoated Prescription Eyeglass Lenses For Optical Usage
Share to:

Clear CR39 1.499 Round-Top Uncoated Prescription Eyeglass Lenses For Optical Usage

  • Bifocal
  • Aogang
  • 9001509900
  • 1.499
  • 70/28mm
  • CR39
  • 58
  • 1.32
  • > 97%
  • UC
  • SPH: -3.00~+3.00 ADD: +1.00~+3.50
Quantity:

Product Show

Product Description

Production

1.499 RT-28 UC LENS

Monomer

CR39

Diameter

70mm

Abbe Value

58

Specific Gravity

1.32

Transmission

>97%

Round top segment

28

Guarantee years

3~5 years

Power range

SPH: 0.00~+3.00, 0.00~-3.00,ADD: +1.00~+3.50


Product Features

  • What Are Bifocal Lenses?

 

Bifocals are two prescriptions combined into a single lens.


Bifocals were originated by Benjamin Franklin in the 18th century when he cut the halves of two spectacle lenses and fitted them into one frame.


Bifocals are needed because the distance glasses do not suffice to focus sufficiently for near. As age increases, (in India 38-40 years is the presbyopic age) reading glasses are required to read at a comfortable distance. Rather than taking out the distance glasses and putting on near glasses each time, a person who wishes to work at the near point could use the lower segment comfortably.

 

There are various types of bifocals available, from the round-top bifocal, flat-top bifocal to the executive bifocal.

 

  • RT-28 Bifocal Lenses

 

The lower half of a bifocal lens contains the near segment for reading and other close-up tasks. The rest of the lens is usually a distance correction, but sometimes has no correction at all in it, if you have good distance vision.

 

One popular fused bifocal is the round seg bifocal. Round-top bifocals are further described by the width of the near segment, measured in millimeters (mm). The most popular RT bifocal is the RT-28, a round-top bifocal with a near seg that is 28 mm wide.

 

An advantage of round seg bifocals is that the line separating the distance and near zones of the lens tends to be less noticeable than the upper line of a D-seg bifocal.

IMG_3227.JPEG


Contact Us

contact us

QUICK LINKS

CONTACT

Add: East Of Nongganxiao, Situ Town, Danyang City, Jiangsu Province, China

Tel:+86-511-86550315
Phone No: +86 18796035231
Fax: +86-511-86555316
Email: admin@ag-optical.com.cn
Copyright  2018 Jiangsu Aogang Optical Glasses Co., Ltd . All rights reserved.   Support By Mmytech   Manage Entrance    Sitemap