How to Choose Lens Index for Your Glasses
Lens index refers to the material's ability to bend light. In general, the higher the lens index, the thinner the lens can be for the same prescription.
If you have a stronger prescription, choosing a higher-index lens can help reduce lens thickness and give your glasses a cleaner, lighter appearance.
Mild prescriptions usually do not need the highest lens index. Stronger prescriptions may benefit more from thinner, higher-index lenses.
What Is Lens Index?
Lens index is a number that describes how efficiently a lens material bends light.
A higher index allows the same prescription to be made with less lens material, which can help make the finished lens thinner.
1.56 Standard Index
1.56 is a standard lens option and is generally suitable for mild prescriptions.
If your prescription is relatively low, a standard index lens may already provide a comfortable and practical result.
1.61 Index
1.61 lenses are thinner than standard 1.56 lenses and are a popular everyday choice for low to moderate prescriptions.
They offer a good balance between lens thickness, appearance, and cost.
1.67 High Index
1.67 high-index lenses are designed for moderate to stronger prescriptions where reducing lens thickness becomes more important.
Compared with lower-index options, they can help create a thinner and more refined finished lens.
1.74 Ultra High Index
1.74 is one of the thinnest commonly available lens options and is generally chosen for stronger prescriptions.
If lens thickness is a major concern, 1.74 may help reduce the thickness compared with lower-index materials.
The best lens index depends on your prescription, frame size, lens type, and personal preference.
Your Frame Can Affect Lens Thickness Too
Lens thickness is not determined by lens index alone.
Your prescription, frame size, frame shape, and pupillary distance can all affect the final thickness of your lenses.
For stronger prescriptions, a smaller or more compact frame may sometimes help reduce visible lens thickness.
Not Sure Which Index to Choose?
If you're unsure which lens index is suitable for your prescription, you can send us your prescription and the frame you're interested in.
We'll help you understand the available lens options before you place your order.
Email: service@rimcoo.com