Lens Index & Material
Lens Index
The index of your lens, also referred to as the index of refraction or refractive index, is a number that indicates how efficiently the material bends, or refracts, light. The higher the refractive index of the lens, the more slowly light moves through it, and the more the light bends. For you, this means a thinner high-index lens will perform the same as a thick set of standard low-index lenses. Additionally, higher indexes are able to handle higher prescriptions. If you have a particularly strong prescription, a lens with a higher index may be the best choice for you. Here at Unieowfa, we offer lenses with indexes up to 1.74.
What Are High Index Lenses And What's The Difference?
High index lenses are thinner, more powerful lenses. They’re lightweight and stylish, but are mostly reserved for those with higher vision correction needs. While most prescriptions are compatible with more than one specific index, it’s up to you to decide which one fits your personal needs!
The difference between your glasses’ lens index can make a huge impact. Deciding which you should get depends on your prescription and your lifestyle. Thicker lenses are more affordable, but can only accommodate lower vision correction needs. Thinner lenses are lightweight (and more stylish!) and can accommodate MANY kinds of vision needs, including higher prescriptions.
-7.00 Degree, Thickness of Different Lenses Index.
1.56 Index — Standard Lenses
(CR-39 Resin)
If you are looking for an economical option for your lenses and have a weaker prescription, these lenses may be the right choice for you.
This index is most suitable for prescriptions with an SPH correction of +/-3.00 and below, or a CYL correction of +/-2.00 and below.
1.60 Index — Thin and Light Lenses
(MR-8 Polycarbonate)
Polycarbonate lenses are the most durable and impact-resistant lenses in our catalog, and come with a 100% UV- protective coating.
This index is most suitable for prescriptions with an SPH correction of +/-5.00 and below, or a CYL correction of +/-3.00 and below.
Note: If you customize rimless prescription glasses, please choose 1.61 index or 1.67 or 1.74 index.
1.61 Index — Thin and Light Lens
(CR-39 Resin)
For people with somewhat stronger prescriptions, these lenses may be a better choice than the standard lenses. These lenses are thinner and stronger than their 1.56-index counterparts .
This index is most suitable for prescriptions with an SPH correction of +/-5.00 and below, or a CYL correction of +/-3.00 and below.
1.67 Index — Super-Thin Lens
(CR-39 Resin)
These lightweight, thin lenses ensure your eyes do not look distorted from a higher prescription. If you have a particularly strong prescription, this is likely the best choice for you.
This index is most suitable for prescriptions with an SPH correction of +/-8.00 and below, or a CYL correction of +/-4.00 and below.
1.74 Index — Extremely Thin Lenses
(CR-39 Resin)
Our thinnest lenses are designed for the highest-powered prescriptions. Any thinner and they would disappear!
These lenses are best for prescriptions with SPH corrections of +/-8.00 and above, or CYL corrections between +/-4.25 and +/-6.00.