Also known as CR-39, this is the industry standard and go-to lens for most patients with low prescriptions. Plastic offers clear visual acuity, but minimal scratch/impact resistance.
Lightweight and tough, polycarbonate is recommended for safety/sport glasses or for people with moderate prescriptions. Thinner than plastic lenses and more impact/scratch resistant, polycarbonate lenses offer 100% UV ray protection.
Phoenix/Trivex is the lightest lens material available worldwide. With the highest strength and extreme scratch/impact resistance, these lenses recommended for safety/sport glasses, drill-mount/rimless frames, children, and moderate prescriptions. Offers 100% UVA and UVB ray protection.
Hi-Index is a compound that creates the thinnest material available, offers high-definition visual acuity. Made in several indexes: 1.60, 1.67, 1.70, and 1.74. Each index represents a thinner and lighter lens. The 1.60 index is about half as thin as regular plastic. Each additional index decreases the lens thickness by almost a third. Hi-Index lenses also drastically reduce or eliminate eye magnification due to far-sighted (hyperopic) prescriptions. Recommended for those with moderate to high prescriptions and especially for those who are far-sighted.