There are a few different lens materials on the market, each with it’s own advantages and disadvantages. It’s the job of a Registered Optician to help you decide the best possible material for your lenses.
Glass vs Plastic
Plastic technologies have advanced enough to effectively make glass lenses history. While glass maintains a few advantages (more stable, less warping over time), they remain a poor option due to their thickness, weight, and the risk to the eye due to shattering. Besides, the optics of plastics (high clarity, low chromatic aberration, etc.) have come so far that their quality can no longer be questioned. Plastic lenses are here to stay.
Plastic vs. Polycarbonate
Polycarbonate is a synthetic resin used instead of plastic lenses when safety is a concern. They are used in all safety and sports goggles as well as glasses for children.
What is a “High Index Lens” and how does it help with thicker lenses?
These lenses are better at bending light. So instead thick lens, you can use a thinner lens to get the same prescription.