Varifocal lenses also known as progressive lenses consist of 3 viewing zones:
Distance zones - the upper area of the lens designed to provide clear distance vision.
Intermediate (Middle) zone - this area allows your eyes to smoothly transition between distance to near vision.
Near zone - the lower area of the lens provides sharp vision close up e.g. reading.
Unlike bifocals, varifocal lenses do not contain a distinct reading segment, usually called a D segment that has a visible dividing line between the distance vision and reading. Bifocals offer a distinct reading segment up to about a third of the lens height from the base. Varifocal lenses gradually change in strength from the top the lens to the bottom.
During transition between the different zones it is possible for distortion to occur. A technologically advanced lens that is tailored to your individual requirements can ensure this distortion is minimised and maximising the field of vision, known as the ‘corridor’. The best lenses will provide the widest field of vision with the least peripheral distortion.
If you haven't worn varifocals before some people get used to them within a few day and others can take 2 to 4 weeks. It is important for your brain to adjust to the different visual experience so if you are struggling over the first few days of use, be patient and persevere with them. Your brain will eventually adapt and enable you to see much better across the whole viewing area. Most people who have had varifocals find they adapt much more quickly to their second pair.
Allow 2 to 3 weeks for your varifocals to be processed. It will depend on the complexity of your order. Clear lenses for glasses will take the least time while lenses that are being fitted into highly curved sunglasses frames that are tinted with multiple coatings will take the longest.
The quality of lenses are determined by the type of lens you choose and the coatings.
We do not compromise with the lens coatings as all progressive lenses will be enhanced by including them. In this respect all the varifocals we offer include our Crystal Clear coatings negating the need to choose most options. These include the following coating:
The only additional coating we offer separately is a Blue Block. This is a High Energy Blue Light filter that help neutralise the blue light emitted by LCD and LED screens preventing eye fatigue and eye strain and even sleeplessness. It keeps the eyes in better condition, offering more comfortable and relaxed vision and a better contrast perception when using everyday digital devices.
For each type of varifocal lens, we offer three levels of quality to meet your needs and requirements. Below we have summarised the difference.
Using the best of conventional lens technology, or entry level digital technology, these are high quality varifocal lenses that provide uninterrupted distance vision with smooth transition increasing power for intermediate and close up.
These are high definition (HD) lenses use the latest free-form technology. They use a digital design process that gives lens designers the ability to reduce lens aberrations even more than they can using conventional lens design and processing techniques with the Premium option above. Lighter and thinner than standard lenses they provide exceptional night/low light vision reducing glare and halo effects from car headlights. They also offer exceptional contrast perception sharpening vision and improved colour rendition providing brighter and more intense colours. This is particularly important for varifocals and highly curved lenses as it ensures they provide the best vision across the whole curvature of the lens avoiding optical distortions that can occur in the periphery area of vision.
Best/High Performance Lenses
These are some of the latest lens designs on the market today. They offer all the advantages of the performance lenses above but are optimised in such a way that they provides a wider distance, intermediate and near area.
In summary, the lens index (i.e. 1.50 index, 1.60 index etc), is the refractive index of the lens material you choose. The bigger the number, the more denser is the material. This translates into thinner and lighter lenses. We have provided a table below to provide an overview to the suggested index based on your prescription sphere strength.
If you require a prescription for industrial safety workwear, sports safety glasses or for wearing sunglasses for impact sports you will need to select either the 1.59 index polycarbonate options or the 1.53 Trivex option. Click on the link for more information on different lens index and materials available.
Guide to selecting the lens index for your prescription:
We offer varifocal (progressive) prescription lenses on all frames that show a ‘Prescription available’ icon below the product image. If you click on the ‘Prescription available’ icon you will only be offered single vision and bifocal options. This is because it is easy to automate the process based on the prescription you provide. However, with varifocal lenses we will need to send the frame out to you so you can take a picture wearing them. We need a picture so that we can accurately measure your pupil from the base of the lens when you are comfortably wearing them and this will vary from person to person. If you are ordering high definition lenses we will also take other data that can be used to improve the accuracy of the prescription across the whole lens that is personal to you. Don’t worry, we will provide instructions on how to do this.
To place a varifocal order just click on ‘Placing a Varifocal Order’ on the side bar.
They will assume an average height for viewing through the lens. Since most peoples faces, nose positions and ear heights are different, it is unlikely that they will be optimised for you. As practicing optometrists we ensure that our online customers benefit from the same care and attention as our patients do in practice. This necessitates that we send the frame out to you first so that we can take the measurements from a picture that you have provided while wearing them in a comfortable position, just in the same way we would do in practice. Whatever range of varifocal lenses you choose, you can then be assured that they will be optimised for you to ensure you benefit from the best vision possible.