Spectacle Lenses
When it comes to choosing your spectacle lenses, there are lots of options available. At the Blackheath Eyecare Centre we will guide you through the different optical lenses and help you make the right choice.
Choosing the right spectacle lenses is critical for two reasons:-
- To ensure your visual requirements are met
- To ensure that your glasses feel and look great.
We will explain the features and benefits of the more popular types of lenses below:-
- Thin and light lenses - Also called High Index lenses
- Anti Reflection Lenses – Also called Multi Anti Reflection Lenses
- Bifocal Lenses – See clearly at a distance and when reading
- Varifocal Lenses - See things clearly at all distances
Thin and light lenses (High Index lenses)
If you have a strong prescription there is no need to have thick and heavy lenses.
In plastic lenses there are 4 grades of lens materials from a standard index lens (CR39) to the super high index lenses (Ultra Thin). The table below highlights how much thinner our ultra thin lenses could be. However, this will be dependant on your prescription. Our dispensing optician will advise you if thin and light lenses would be beneficial and show how much thinner they will be. We will also take into account your frame choice as this also has a key bearing on how thick your lenses will be.
Standard lenses
Thin lenses
Super Thin lenses
Ultra Thin lenses
Standard index (1.50)
Mid Index (1.60)
High Index (1.67)
Super-high Index (1.74)
Standard thickness
up to 30% thinner
up to 40% thinner
up to 50% thinner
An even higher index lens is available in glass so they can be made even thinner. They are available in an ultra high 1.9 Index. Generally plastic lenses are suitable for most prescriptions and are the first choice as plastic lenses are lighter and safer.
As independent opticians, we, at the Blackheath Eyecare Centre can choose the best lenses from all the top optical lens manufacturers. We have great lenses across our whole price range.
All high index lenses that we use automatically come with a reflection free coating. Our top end brands also include an “easy clean” coating and come with a 2 year guarantee.
We specialise in complex lenses and often recommend custom made surfaced lenses. These lenses can significantly reduce the thickness on longsighted prescriptions. We will automatically use custom made lenses if you would benefit from them. Stock lenses tend to be used on lower powered prescriptions.
Another type of lens we would automatically use is the “Aspheric lens”. This is less curved than a standards lens. The less curved the lenses are, the flatter and thinner they will be.
Anti Reflection Lenses
Standard plastic lenses (CR39) transmit 90% of light to the eye. 10% of light is lost through surface reflections. The new generation Anti-reflective lenses transmit more light and reduce reflections which provide the following benefits:
- Better for driving - Improved night vision
- Better looking glasses - Improves your appearance
- Better for working - Reduced eye strain
- Better durability - Lasts longer
Anti Reflection Lenses - Better for driving
Anti-reflective lenses provide you with improved safety and faster recognition of potential hazards on the road, especially at night. The reflections of streetlamps and headlights on your lenses are virtually eliminated.
You want this:
Not this:
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Anti Reflection Lenses – Better looking glasses
People want to see your eyes. Eye contact is one of the most important aspects of interpersonal communication, and reflections from your glasses get in the way. These exceptional anti reflection lenses help you enjoy direct eye contact unhindered by distracting reflections.
You want this:
Not this:
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Anti Reflection Lenses – Better for working
Artificial light in an office environment quickly leads to eye fatigue as much as working on the computer can put a strain on the eyes. Anti reflection lenses can help give you a clearer and more comfortable vision.
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Anti Reflection Lenses – Better durability
Anti-reflective lenses are also scratch resistant, which improves the durability and life of your lenses. This extra protection means that the lenses maintain clearer vision for longer.
Our top end brands also include an “easy clean” Anti Reflection Lens and comes with a 2 year guarantee.
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Bifocal lenses
Bifocal lenses are corrective lenses prescribed to people with presbyopia who need both a separate near and distance vision correction.
Some people choose to have separate pairs of glasses for reading and distance, however the majority of people prefer the convenience of one pair.
There are many designs of bifocal lenses all of which have a visible dividing line that separates the distance and reading portion. The picture below highlights these areas in blue and purple.
Bifocals are a good solution for maintaining clear distance and reading vision at the same time. They are excellent in proving large clear distortion free areas for both distance and reading.
One disadvantage of the bifocal is the demarcation line, which separates the near and distance prescription. Another concern of the bifocal is the increased difficulty of viewing intermediate tasks such as the computer screen. Varifocal Lenses have been designed to help solve the limitations of bifocals.
Our bifocal range of lenses are available in the thin and light lenses and also in Photochromatic (Transition) lenses.
Varifocal Lenses - See things clearly at all distances
Varifocal lenses are corrective lenses most commonly prescribed to people with presbyopia who need both a separate near and distance vision correction.
They allow you to see clearly at all distances with just one pair of spectacles without any abrupt changes or visible lines in the lens.
The picture below shows the different areas of the lens. The lenses are designed so that when looking straight ahead you automatically look through the distance portion of the lens (shown in blue). The lower portion of the lens is the reading zone (shown in purple). The middle portion of the lens allows you to view anything at arms length (shown in yellow).
Varifocal lenses take a little time to adapt to. Once you get used to these types of lenses you will find that you can see clearly at all distances.
Varifocal lenses are available in numerous designs. The differences in designs refer to the areas allocated to the distance, intermediate and reading zones.
Some older varifocal designs have large distortion zones which can make them more difficult to adjust to. We at the Blackheath Eyecare Centre use newer technology that reduces the size of the distortion areas making them easier to adjust to. These lenses provide significant wider viewing zones therefore giving a much clearer more comfortable vision.
As independent opticians we choose the best lenses for you from a number of different optical lens manufactures. We always put your needs first and base our recommendation on your lifestyle requirements.
On the whole, the success rate is extremely high. The newest designs of Varifocal lenses are easier to get used to. A small number of people may not get used to wearing varifocals. That is why we will give you a 30 day varifocal exchange warranty. If you do not get on with them they can be exchanged to bifocals or single vision alternatives.