What is the right lens index for you?

With the ever-increasing advancements in lens technology, there are more choices than ever when it comes to purchasing eyeglass lenses. Standard, polycarbonate and high index - what do all the different lens products mean to you?

What is the lens index?

The lens index is a numerical representation of the refractive power of the lens material, which determines the thickness of the lens. Certain materials, especially those in high-index lenses, bend light more efficiently. Made from higher quality materials, high index lenses will be able to provide stronger corrections without the need for thicker lenses. As the prescription strength increases, the lenses become thicker and heavier. High-index materials provide thinner and lighter lenses, which is a good option for those with strong prescriptions. Typically, the exponent ranges from 1.50 to 1.74.

What is a high index lens?

Lenses with a higher index of refraction slow and bend light more effectively than standard index lenses. Due to the quality of the material, the light is used more efficiently, so no additional material is required to change the path of the light.
Simply put, if you have high index lenses, they will be thinner. Conversely, if your prescription glasses are fitted with a lower lens index material, they will be thicker.
The lens index charts range from a 1.5 standard index to a 1.74 high index.

Lens material

The quality of the lenses is measured on the Lens Index chart. Differences in eyeglass lens indices can have a huge impact on your lifestyle. Low lens index glasses will be thicker but more affordable and offer only a low level of vision correction. High-index lenses have less material, making them thinner, lighter, and customizable to address a wide range of vision correction problems.

1.5 Standard Index
1.5 Standard index lenses are for the weakly prescribed population looking for an affordable option.
1.5 Standard refractive index lenses are available for the following prescriptions:
+/- 2.25 and less SPH correction, or;
CYL Correction +/- 1.50 and less

1.56 Intermediate index
The core difference between a 1.56 medium index lens and a 1.5 standard lens is the thickness of the lens.
The 1.56 thin index lenses are suitable for the following prescriptions:
SPH correction of +/- 5.00 and +/- 4.00, and;
CYL correction of +/- 3.00 and below

1.61 High Index
1.61 high-index lenses offer a slim option for those looking for a modern, stylish look. The 1.61 high index lenses fit into thin frames, making them ideal for everyday wear.
1.61 High index lenses are suitable for the following prescriptions:
SPH correction of +/- 4.25 and +/- 6.75, and;
CYL correction of +/- 2.25 and +/- 3.00

1.67 High Index
The 1.67 high-index lenses are very thin, even surpassing the 1.61 high-index lenses. This lens index is a great option for those with a super prescription.
1.67 High index lenses are suitable for the following prescriptions:
SPH correction of +/- 7.00 and +/- 9.00, and;
CYL correction of +/- 3.25 and +/- 4.00

The 1.74 high index lens is the thinnest option available, designed for those with the highest prescriptions, and is the best option if you have a high prescription.
1.74 High index lenses are suitable for the following prescriptions:
+/- 9.25 and higher SPH correction, and;
CYL correction of +/- 4.25 and +/- 6.00

Shopping at ANRRI

In order to find the best frame, no matter what your lens index, ANRRI not only offers all of them but just like your optometrist, we will give you the right index of lenses according to your prescription, our online ordering system automatically recommends the best index for your prescription! Plus, ANRRI can offer any variety you want, combined with our innovative lens technologies such as blue light filter glasses and sleep glasses.