Lenses Index determines the thickness of the lens. The highger the Index, the thinner is the lens. Higher index is worth paying for. It is especially importat for higher prescriptions over +/-4.00 Sphere.
Anti-reflective coating blocks reflection from the outside light and allows your to see clearer. People who are looking at you, will see your eyes instead of seeing the reflection of the lenes.
Transitions is an option that makes your lenses adapt to light and change lenses tint depending on where you are. When you are indoors, lenses stay clear. When you are outdoors, depending on how bright it is, lenses will turn dark mimicking, sun lenses tint.
Polarized is an option added to sun lenses. Polarized lenses cut the glare from horizontal surface such as road, snow and water. No glare, better vision!
