What is the corridor? What are the difference between 12+2, 12+4 and 9+4?
Corridor is a physical parameter of progressive lens, with the longer corridor, lens can suits with more bigger / flexible sizes of frames.
Different corridor option will suits different needs of clients, like:
- For patient: If you’re the person who wear progressive lens at 1st time, 12+2 is highly recommending because it can makes you feel comfortable when near and far use.
- For patient’s prescription: If the near vision prescription is big difference compare to the far vision’s prescription, 9+4 corridor is highly recommending
- For purpose: If you’re using the outdoor activities mainly, 12+2 is highly recommending also.
- For different frame size options: 9+4 corridor suits small size frame; 12+2 suits standard size frame; 12+4 suits big size frame.
Here are three power plots for corridors for your reference.



Corridor option should be recommended by optician usually, a good optician, they have the ability to advise you base on the evaluation of your prescription / frame size and usages.
We had been developed 12+2 70mm, 12+4 75mm and 9+4 75mm corridor of progressive lenses, with the prescription of SPH -3.00~+3.00, ADD +100~+300.
And there are specific corridor designs of progressive lenses. We will share you if you can send us message if this data interest you.
Contact us to get samples to check.



