You must have the experience of wearing thin curve lenses if you ever have a high prescription, that as we called "Coke-bottle" lenses, maybe it's time for you to try high index lenses now, they can be much thinner than ordinary lenses at the same prescription!

And a AR-coating is a must for high index lenses, because this kind of lenses can block much more light light which come to the lenses than ordinary lenses, just about 57% of the total light, and a AR-coating can improve the transmittance as much as 99%.