Lens index describes the thickness of your optical lens - a higher lens index indicates a thinner lens. Lenses with a high index are thinner and more powerful. They're light and fashionable, but they're mostly recommended to those who require a higher vision correction. While multiple indexes can be used for most prescriptions, it is up to you to decide which one fits your personal needs.
- 1.50 index are conventional standard lenses. They are suitable for prescriptions of +/- 2.00 or below. They can effectively correct a CYL of +/- and below.
- 1.53 index are trivex lenses. They are thinner than the regular 1.50 index lenses are impact-resistant. They are recommended for corrections of +/- 2.25 and for CYL corrections of +/- 3.00 or below
- 1.59 index polycarbonate lenses are the most impact-resistant option and block 100% of UV rays making them the most suitable option for children's glasses.
- 1.60 hi-index lenses are thinner and lighter than polycarbonate lenses and are recommended for sphere corrections of +/-6.50 or below and CYL corrections of +/- 3.00.
- 1.67 super hi-index lenses offer lesser distortions and are recommended for corrections of +/- 9.00 or below and CYL corrections of +/- 4.00 or below.
- 1.74 ultra hi-index lenses are the thinnest possible lenses and handle the highest prescriptions. They are for corrections of +/- 9.00 or greater and for CYL corrections greater than +/- 4.00.
The difference in lens index can have a huge impact on how your glasses look. Your prescription and lifestyle determine the kind of lens index that you might need for your glasses. While thicker lenses are economical, they are only suitable for people with lower vision correction needs. Higher index (thinner) lenses are lighter and more fashionable and can meet a wide range of vision correction needs, including high prescriptions.