Types of Lenses
Polycarbonate lenses are the most impact resistant lenses available and are recommended by Heartland Optical because of their versatility. Polycarbonate lenses are lightweight, durable, and safe. They absorb all harmful UV light and come equipped with scratch coating on both sides of the lens.
Polycarbonate was developed in the 1970s for aerospace applications, and is currently used for the helmet visors of astronauts and for space shuttle windshields. Eyeglass lenses made of polycarbonate were introduced in the early 1980s in response to a demand for lightweight, impact-resistant lenses.
Lighter, Thinner Lenses (Hi-index)
Modern technology has created lenses that bend light differently so that stronger corrections are thinner than when made in conventional materials. Such lenses are called “high index” and stronger corrections are more attractive because they are thinner. High index lenses absorb all harmful UV light and come equipped with scratch coating.
Hard Resin (Plastic)
CR-39 lenses, also known as plastic lenses, are one of the most common materials for lenses. Plastic lenses became popular during the 1970s due to the fashion trend for large-sized frames. Plastic (also known as hard resin or CR-39) lenses are half the weight of glass lenses, which made them more comfortable. Plastic also provides excellent optics and vision correction. To overcome the softer lens surface, scratch resistant coatings are available and always recommended.
The newest material in the optical world. Trivex provides the impact resistance of polycarbonate with the clarity of glass. They are lightweight, durable, safe, but are thicker than polycarbonate or hi-index.
The oldest of lens materials. Glass lenses are becoming obsolete in the lens marketplace today because of the advances in the materials listed above. Glass is heavy but very scratch resistant. For patients that strongly believe in glass we have it available.