What does lens index number mean? What are High Index Lenses? How do I choose the high index lenses?
The Lens Index number (1.56, 1.61, 1.67, or 1.74) refers to the degree of refraction the lens provides, indicating how much the light that enters the lens is refracted (bent) as it passes through the lens.
Lens Index is also related to the thickness of the lens. The higher the index, the thinner the lens will be.
High index lenses are thinner, more powerful lenses. They're lightweight and stylish, but are mostly reserved for those with higher vision correction needs.
Recommend Index Number
| Image | Lens Index | Features | SPH |
|---|---|---|---|
 |
1.56 INDEX LENS | For people with moderately-strong prescriptions. Thinner and lighter than standard lenses. | -0 to -3.00 |
 |
1.60 INDEX LENS | Stylish and extra-thin. Great choice for stronger prescriptions. | -3.00 to -5.00 |
 |
1.67 INDEX LENS | Extremely thin. Good choice for extra-strong prescriptions. | -5.00 to -8.00 |
 |
1.74 INDEX LENS | As thin as possible. Best for the highest prescriptions. | -7.00 and above |
While most prescriptions are compatible with more than one specific index, it's up to you to decide which one fits your personal needs!