Thinner lenses (High refractive index lens)
The higher the power in your prescription, the thicker the lenses. This is where thinner (High index plastic) lenses are a better choice. High index lenses can bend light more efficiently than the standard lenses. This means, less lens material is needed to correct the prescription. This makes the lens thinner and therefore lighter too. The higher the refractive index, the thinner the lenses.
20% thinner than standard lenses
1.61 High index lens cost £35. It is a good option if your prescription is roughly + or - 1.75 to 2.50
30% thinner than standard lenses
1.67 High index lens cost £55. It is a good option if your prescription is roughly + or - 2.75 to 3.75 40% +plus thinner than standard lens
40-50% thinner than standard lenses
1.74 High index. This is a good option if your prescription is roughly + or - 4.00 & above £85