Bifocal lenses assist with distance vision in the top and up-close vision in the bottom of the lens, but have a visible line that is distracting from both sides – wearers also experience an “image jump” when moving between viewing distances.
Trifocal lenses assist with distance, mid-range and near viewing, but have even more distracting lines and image jumps that get in the way of good vision and good looks.
Some of us need different strength lenses for distance and close up activities. One solution to this is to have a separate pair of spectacles for each e.g. one pair for reading, and one pair for watching TV or driving. With Bifocal lenses you only need one pair of glasses as they have two prescriptions within one lens, usually reading in the lower half and distance in the upper. This means that you only need one pair of glasses whether you are reading a newspaper or watching TV – or both!
Kodak Bifocal Lenses are available in a choice of materials from conventional through to 1.6 Thin & Lite plastic. These can be enhanced with many different options, from anti-reflection coatings to fast-reacting sun lenses. Whatever your lifestyle, we can make a lens for you.
Many Kodak Bifocal Lenses have the added advantage of having an aspheric design. In an aspheric design, the lenses have flatter curves. This means that they do not “bulge” out of the frame as much as regular lenses. The side profile of aspheric lenses is thinner, which greatly enhances the appearance of finished spectacles. They also give enhanced overall vision especially in higher prescriptions.
Kodak Lens provides innovative spectacle lens products and some of the most advanced spectacle lens technology in the world. Our global research and development teams are constantly working to develop the ultimate materials and designs.
The importance of lenses often gets overlooked when people are choosing their new spectacles. Frames are obviously important to the aesthetic appeal, but many people are unaware of the lenses available and how what they can offer to give you greater vision.
How we make Kodak Lenses
There are many technical processes that go into making a Kodak Lens and making them precise to your prescription and to your lifestyle.
Step 1: Semi-Finished Lenses
These lenses are produced in our manufacturing plants around the world, by injecting molten monomer into optical moulds which are then cured to give a semi finished lens with a perfect front surface with a precise optical curve on it.
The back surface of the lens will be processed in our laboratory to a given curve. The combination of the moulded front curve with the processed back curve produces a lens of a given prescription.
A semi finished lens could be used as the starting point for lenses of many different prescriptions – the finished prescription will be determined by the amount of material that is processed away from the back surface and the curve that is left on this surface.
Step 2: Lens Design
After your eyecare practitioner has tested your eyes and determined the prescription of the lenses you will require for your spectacles, and you have decided with him/her which type of Kodak Lenses will be best for you, they will take a number of facial measurements from you such as the distance between your pupils, to ensure the correct fit.
Our skilled Lens Technicians will then computer generate the best design for your lenses in terms of their appearance and optical performance – they calculate exactly how we will process the back surface of the semi finished lens.
Step 3: Blocking
The perfect front surface of the semi finished lens is masked and protected throughout the lens production process. A metal ‘fixing block’ is attached to this surface at a very precise angle which is determined by your prescription. This ‘block’ allows the lens to be held in the generators in exactly the right position to produce the right lens curves for your prescription.
Step 4: Generating and Smoothing
The ‘blocked’ lenses go into the generating machines individually.
The required curves are entered into the generators and automatic cutters then grind away, then smooth the back surface of the lens until the curves are exactly right for your prescription.
Step 5: Polishing
The back surfaces of your lenses are now polished using specialist polish and polishing pads so that a perfect back surface is created to match the still protected finished front surface.
The lenses are checked and inspected at each stage of production – cleaning is carried out using water and compressed air and handling is kept to a minimum.
Step 6: Quality Control
The lenses next go through a thorough checking procedure to make sure that they precisely match the power and specifications that your eyecare practitioner has ordered for you and that the lens surfaces are perfect.
Step 7: Coatings
Next stop for your lenses is the dust-free, space age environment of the Kodak CleAR Lens Coatings laboratory. Here the lenses go through a thorough cleaning and drying process – they are placed in special holders, dipped into a series of ultrasonic tanks and are then oven dried for some 4 hours.
Step 8: Kodak CleAR lens coating
Some lenses will just have a scratch resistant coating applied to them, but more and more people choose to have a Kodak CleAR or Clean’N’CleAR anti reflection Lens coating applied, as this makes the lenses much better to look at, and to look through, as there are no distracting reflections.
Kodak CleAR and Clean’N’CleAR anti reflection Lens coatings are applied to your lenses in a high-pressure vacuum chamber. They are produced by the precise deposition of specially selected chemicals on the lens surface – 12 layers are applied to each side of the lens in a fully automated, computer controlled process. It is hard to believe but the thickness of this coating is less than 3 microns (i.e. less than the width of an average strand of hair).
Step 9: Glazing
Once your lenses have been coated, they will then be cut to the right shape for your frame using computer controlled glazing equipment – an automatic tracer follows the inside rim of your frame telling the machine the shape required, your measurements are entered and the edging machine then ‘edges’ the lens to the required shape.
Step 10: Finished Lenses
After a final thorough inspection your lenses are carefully packed and despatched to your eyecare practitioner who fits them into your chosen frames to complete the fitting procedure.
In most cases the lenses are protected by RLX Plus (The World’s most scratch resistant plastic lens surface)
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