A high index lens is a lens that has a higher “index” of refraction. This means it has a greater ability to bend light rays to provide clear vision for people with stronger prescription glasses. But that’s the technical terminology. What do high index lenses mean for eyeglass wearers?
Thinner, lighter, and more visually appealing, that’s what! High index lenses are manufactured to be thinner at the edges of the lens and lighter in weight overall.
High index lenses are a good option for people who have strong prescriptions for myopia—commonly called “nearsightedness” due to a difficulty in focusing on far objects. A high-index lens can bend light rays more while using less material in lenses created for both nearsighted and farsighted people (hyperopia).