How to choose the right lenses
Your lens index. The lens “index” is short for the lens’s “index of refraction.” That means how much the lens bends the light that enters it. That’s what refraction is. Bending the light focuses it right into the middle of your visual sweet spot, the retina, so you can see well.
You can change the index to thin the lens, up to a point. After that point, the law of diminishing returns kicks in. The lens that is recommended for your prescription will be the thinnest lens. Choosing a lens index that’s higher than the recommended lens index won’t make the lens thinner, and you’ll end up paying more for no improved result.
This handy online tool is the Lens Thickness Calculator. It can be found here, at the OptiCampus website.
Choose suggested index based your sphere powers,
|0.00 ~ -3.00||1.56 Lens|
|-3.00 ~ -5.00||1.61 Lens|
|-5.00 ~ -7.00||1.67 Lens|
|> -7.00||1.74 Lens|
Choose the right lens based on your needs,
|Blue Light Filtering||For those regularly using computers or digital devices|
For those always looking for high-quality facewear, thin and lightweight lens or people with strong astigmatism
|Generic VS Imported||Generic lens are made in China; Imported lens are imported from Korea or Japan|