What Types of Lenses Are Available?
As technology advances, so do lenses. In the past, they were made exclusively of glass. Today, most are made of high-tech plastics. These new ones are lighter, don’t break as easily as glass, and can be treated with a filter to shield your eyes from damaging ultraviolet (UV) light.
The following lenses are lighter, thinner, and more scratch-resistant than glass or the older plastic types.
Polycarbonate. These impact-resistant lenses are a good choice if you play sports, work where your eyeglasses could easily get damaged, or have kids who are tough on their specs. They also have built-in UV protection.
Trivex. They’re made from a newer plastic that’s similar to polycarbonate lenses. They’re lightweight, thin, and impact-resistant. They may also correct vision better for some people.High-index plastic. If you need a strong prescription, these lenses are lighter and thinner than the old-school super-thick ones you may have had in the past.
Aspheric. These have various degrees of curvature. That means they can be thinner and flatter so you can use a much larger portion of the surface.
Photochromic. Sunlight changes these from clear to tinted. You may no longer need sunglasses, although they may not darken in your car if the windshield blocks UV rays. They can be either glass or plastic.
Polarized sunglasses. These lenses reduce glare from a surface like water, so they’re great for sports and driving. But they can make it hard to see the liquid crystal display on your car’s dashboard.
Your type of vision problem will determine the shape of your lens. You’ll need a concave lens (curves inward) if you’re nearsighted. A convex lens (curves outward) will help if you’re farsighted. If you have astigmatism, your cornea is shaped wrong, so your lenses may be more like a cylinder. Simply put, the lens is a tool you use to focus light onto your retina in the correct way.
