Choosing Your Lenses
Lenses exist in different materials and options (coating, tint, index). Depending on your vision deficiency and the comfort you expect, you might want to understand well before purchase the different options available to you.
Materials
Plastic or Organic
This is the material the most used around the world. They exist in all shapes, forms and options and provide a very good quality/price ratio.
Polycarbonate
Polycarbonate provides 2 advantages over the plastic ones:
- Harder to break (plastic lens tend to break under pressure; it can be important for children use,
sport use or rimless/semi-rimless frames)
- Higher index (hence the lens is thinner than a plastic one unless you take a higher index option
with your plastic lens)
Options
Coating
Lens manufacturers use technology in order to offer us many different coating types and qualities in order to increase their offers and potential margins. One needs a big manual in order to understand them and figure out what is one’s need. Trying to simplify a little bit in order to facilitate your choice:
Scratch Resistant
As its name indicates it, this will provide a longer life to your lenses as minor scratches won’t occur as much. However this does not mean that a contact with a hard, resistant material won’t scratch it! They usually come by default with all lenses.
Anti-Reflective
Manufacturers innovate periodically into this field bringing higher transparency and vision to the bearer who might need them due to his sight or the conditions in which he wants to use his spectacles (driving, reading, beach use, …).
Several options exist:
- Basic Anti-reflective (AR): this is the most common one and will bring the bearer a clearer view thanks to less light reflection on the lenses. It is a recommended option in most cases.
- Essilor Cryzal©: Offered by Essilor, one of the first lens manufacturer in the world, it provides clearer view by a factor of x (to be defined) than the Basic AR.
- Essilor Cryzal Alyze©: Offered by Essilor, it provides clearer view by a factor of x (to be defined) than the Cryzal method.
UV400 protection
UV400 protection is a clear coating which offers you complete UV protection against the sun’s rays. It is available in clear or tinted coatings. By selecting a tinted UV you can turn your prescription glasses into prescription sunglasses.
High Index
Lenses are also measured by their refractive index. Common lenses bear a 1.5 index and it can go up to a 1.74 index. The higher the index, the thinner the is lens allowing a strong prescription (with high dioptres) to wear thin lenses like the others (hence lenses are also lighter). Indexes are usually presented as ‘thin’, ‘ultra thin’, ‘ultra ultra thin’.
Tints and Transitions
You can also tint your lenses in order to obtain sun glasses with your regular frames. This allows you to correct your vision as well as shade your eyes from the sun. Up to 10 colors are usually available and you can also ask for gradient tint (from the color you wish to ‘white’). Transitions are photo sensitive lenses that darken from clear to tinted color in bright sunlight. This gives you the freedom to wear your glasses as prescription sunglasses in bright sunlight, whilst having a clear lens for indoor and evening use. Please note that transition lenses are available in brown and grey and are only compatible with standard and polycarbonate lenses. Tints are available in a choice of 4 colors.
Polarization
Polarization is a process through which the lens is put which polarizes light (aka. it diffuses the concentrated light waves). This filtering process eliminates 99% of the reflected glare. Light reflected from surfaces like a flat road or smooth water is generally horizontally polarized. This horizontally polarized light is blocked by the vertically oriented polarized filter in the lenses. Polarized lenses are usually used for driving or intense light environments like when you run an outdoor activity or sport.
Which Prescription, Which Lens?
For the best cosmetic finish and comfort on your spectacles, we strongly recommend that you follow this guide: • Prescriptions between -2.50 and + 2.50 should use a standard or polycarbonate lens • Prescriptions between +/- 2.50 and -/+ 5.00 should use a thin or polycarbonate lens • Prescriptions over -5.00 and +5.00 should use a super thin lens Obviously if you have a lower prescription but want the lightest possible lenses we can always accommodate your wish.
\n"; */