As we discussed in the previous article, the progressive lens supports multi-focal lengths, this makes progressive lens very complex. So it needs precise eyesight measurement and careful manufacture. First of all you should select a proper frame for progressive lens. The components of frame you have to be concerned with are as follows:

1. Size of the frame - The frame should be a perfect fit to your face.
2. Shape of the frame – If the shape can cover all the distances: reading distance, middle distance, and far distance, this is the best choice. But there’re also different lens designs that can support some specific frame shapes.
3. Height of the frame – the frame should not too short otherwise it cannot cover all the distances of the lens.
4. Pantoscopic Tilt – should be 10 – 12 degrees.
5. Curvature Angle – should not be too curved, otherwise it will cause chromatic aberration.
6. Vertex Distance – should be 12 – 14 mm.
7. Temple Length – should well fit to your ears
8. Strength of frame – the frame should be strong enough, not so easy to bend, in order to keep the above components stable.
9. Having adjustable nose pad – adjustable nose pads can help an optician in adjusting or fitting the frame to your face.

Each component relates to each other. For example if the frame is too small or temple length is too short, then the pantoscopic tilt will be too much, and will cause distortion. If the temple length is too long, then the frame will fall down, and you will find it difficult to read. After you have selected a desired frame, the optician will suggest the suitable lens design for you. Or if you really need a specific lens design, you have to find the frame which fits to that lens.

The accurate measurement of P.D. (Pupil Distance, the distance between both of your pupils) for reading, P.D. for far distance, Fitting Height (the height from the frame lower border to each of your pupils are also very essential. Moreover, the opticians’ dispensing skill and their familiarity with each lens design are also important. (Normally, the opticians will suggest the product they usually use) so be careful when you choose an eyeglass shop.

These days a lot of manufacturers offer a tailor made progressive lens where opticians have to send all the details to the lens manufacturer e.g. lens powers, P.D. for reading, P.D. for far distance, fitting height, pantoscopic tilt, vertex distance, frame details, etc. The manufacturer will then produce a specific lens for you. Of course, we assume that the tailor made lens will perfectly solve your eyesight problem.

After you receive the new progressive eyeglass, the optician must explain how to use it. Try to practice for a couple of days, and then if you get used to it, you will be able to see smoothly in every distance. But if you’re not comfortable using the new glass, have a headache or cannot see clearly in some distance, don’t wait, just go to the eyeglass shop and discuss it with them. If you’re sure that you had done everything right, then don’t hesitate to ask them to build a new pair of lenses for you. The important thing is that you have to take care of your eyeglass in order to keep all the components stable. If you bend it or even break it, a flaw might occur.