LENS GUIDE / OPTICALH
Thinner lenses.
More than a number.
Index describes how a material refracts light. It can help reduce thickness, but your prescription and frame also influence the choice.
Conceptual negative-lens profiles, not to scale. This is not a prescription example or a calculation of millimetres or percentage savings.
Four indices, one personal choice.
These numbers are not quality grades or automatic recommendations based on dioptres. Compare the options available in your configuration.
1.50Standard
A starting point for comparing other options.
What to considerIf it delivers a suitable result with your prescription and frame, you need not automatically choose a higher index.
1.60An intermediate option
An option to explore reduced thickness compared with a standard material.
What to considerCompare the expected result and cost with the same prescription and frame.
1.67High index
Another option when reducing thickness is a priority.
What to considerDoes not, by itself, mean an aspheric design or compatibility with every mounting style.
1.74The highest of these four
May be useful when thickness reduction needs particular attention.
What to considerDoes not guarantee the lightest lens or automatically make it the best choice for you.
What changes the result.
Your full prescription
Do not use only the highest sphere or ignore the signs. Cylinder and axis are also part of the correction.
Your frame
Size, shape and centration influence final thickness. A different frame can change the comparison.
Material and design
Index, density and optical geometry are different properties. Thinner does not always mean lighter.
Before you decide.
Can I choose an index from my sphere alone?
Do not treat a table of fixed cut-offs as a prescription. Share your full prescription and frame; ask us before completing your selection if an option is unclear.
Does high index mean aspheric?
No. Index describes the material; aspheric describes a surface geometry. Check the design of the specific lens.
Can any index be used in a rimless frame?
Compatibility depends on the material and mounting requirements, not index alone. Do not assume that every lens of 1.60 or above can be drilled.
Are the same coatings included?
That depends on the selected lens. Check your configuration’s options, compatibility and price; this guide does not change the included features.
The right index, with a clearer picture.
Have your prescription and frame model ready. We can explain the options shown in your configuration.
