Optical London Drugs offers four different lens thickness options. What's the best one for you? 

 

Our FREE lens / The Standard Lens

1.5 Index: These are typical eyeglass lenses that accommodate lower prescriptions well. They are slightly thicker than the other lenses we offer and they come FREE with any frame purchase. We add an anti-reflective coating to help reduce pesky glare and halos-- also free of charge. 

High Index Lenses 

High index lenses are thinner and accommodate higher prescriptions better than thicker lenses do. If you have a high RX, a high index lens may be the right choice for you. They also tend to look better in very thin frames than standard lenses. 

1.6 Index: These are thin, stylish lenses that are great for people with RXs that have a sphere (SPH) between +/- 4.25 and +/- 6.75 and a cylinder (CYL) between +/- 4.25 and +/- 3.00. We offer a free anti-reflective coating with these lenses. 

1.67 Index: A very thin lens for a people with very strong RXs. We recommend these lenses if your prescription has a sphere (SPH) between +/- 7.00 and +/- 9.00 and a cylinder (CYL) between +/- 3.25 and +/- 4.00. We offer a free anti-reflective coating with these lenses. 

1.74 Index: The thinnest lenses currently available. These lenses are for people with the strongest prescriptions. If you have a sphere (SPH) between +/- 9.25 and a CYL between +/- 4.25 and +/- 6.00, these lenses are for you. Like our other options, these lenses come with a free anti-reflective coating. 

 

In general, if you have very basic vision correction needs or don't wear your glasses all the time, the standard 1.5 index lens should be a fine choice for you. For people who want something a little fancier, or people who need a high index lens by necessity of their Rx, high index lenses accommodate all prescription types and are a sleek, stylish, lightweight lens choice.