When it comes to eyeglasses, choosing between colors, details and silhouettes can make your head spin, especially when you realize the options don’t stop at frames. The number of lens coatings and materials have ballooned over the past decade — and that can be unnerving when you’re trying to spot the perfect pair.
According to a recent VisionWatch survey, The Vision Council’s large-scale consumer survey, an estimated 160 million American adults wear glasses. And many are largely unaware of the implications of their lens buying decisions.
“Doing your own research will put you at ease and help the eyeglass selection process along,” says Dr. Justin Bazan, New York-based optometrist and medical advisor to The Vision Council. “However, no matter what choice seems like the right fit, be sure to consult with your eyecare provider before making the decision.”
Here’s a breakdown of lens materials and lens coatings so you can select the best lenses for your unique needs.
- Plastic (CR39). Plastic lenses are half the weight of glass lenses but have a softer surface, making them easier to scratch. “Scratch-resistant coatings provide a harder surface and come standard on most lenses,” says Dr. Bazan. Both glass and plastic must be treated to offer ultraviolet (UV) protection, since it’s not inherent in the material.
- Trivex® Plastic. Trivex is a unique material that provides great impact resistance and is the lightest weight of any lens materials available. It also has the added benefit of blocking UV radiation and comes with a scratch-resistant coating.
- Glass. Glass lenses are much less popular these days, but they still provide excellent optical quality and a scratch-resistant surface. The rub: Glass is twice the weight of comparable plastic materials and must be treated to comply with the Food and Drug Administration’s (FDA) impact resistance requirements.
- Polycarbonate. When your prescription gets a little higher, your vision care provider may recommend polycarbonate lenses because of their higher index. They’re also tougher and more impact resistant than CR39 which makes them perfect for children and active adults. They’re also thinner and lighter than conventional plastic or glass. A bonus: All polycarbonate lenses come with UV protection and scratch-resistant coating.
- High index plastics. High index plastics are the lens of choice for people who have high-power prescriptions. They are lighter and thinner compared to lower index materials and they provide UV-protection and scratch-resistant coating. High index glass lenses are also available, but they’re much heavier than the plastic variety.
- Scratch-resistant. Scratch resistant coatings make lenses tougher. Today, most glasses come standard with scratch resistant coating.
- Anti-reflective. Anti-reflective (AR) coatings help reduce reflective glare. So, when you’re driving at night, you won’t see lights reflecting off the lens and into your eye. “Premium AR coatings often include a hydro-phobic and olio-phobic finish to repel water, finger prints, smudges and oils to make the lenses easy to clean and maintain,” says Dr. Brandon Or, practicing New York-based optometrist – and that’s a plus for teachers who don’t have time to wipe down their glasses during a lecture.
- Ultraviolet (UV) coating. These days most lens materials offer some UV protection. Materials like polycarbonate and high index materials do a good job at blocking out UV radiation, but others, such as regular glass and plastic lenses must be specifically treated to provide protection against UV light.
- Mirror coating. Want to keep your students on their toes? These lenses allow you to scan the playground without anyone seeing your eyes. Instead of absorbing light the way most sunglasses do, mirror-coated lenses reduce the amount of light by partial reflection so the light that is not transmitted is reflected. “It’s like a two-way mirror,” says Dr. Or. The downside: Mirror coatings can create back surface reflections and it is highly recommended to add an AR treatment to eliminate the reflections.
- Photochromatic lenses. People who are sensitive to light might benefit from photochromatic lenses because they automatically darken when exposed to the sun’s rays and lighten in their absence. “You don’t have to worry about remembering to pop on your sunglasses, because the coating darkens when you go outside,” says Dr. Bazan.
- Polarized lenses. These lenses are a great choice for people who do a lot of sailing, fishing or snow skiing. Unlike regular sunglasses, polarized lenses block glare, not just brightness. Polarized lenses are available in a variety of materials, colors and can also combine polarizing effects with photochromic coatings.
- High Energy Visible (HEV/Blue Light) Filter. High Energy Visible (HEV) light is the light on the low end of the visual color spectrum, also referred to as blue light. A primary source of HEV or artificial blue light comes from electronic devices and energy efficient lighting, such as LEDs. A lens treatment to filter some of this blue light may help minimize the symptoms commonly associated with digital eye strain from prolonged screen use.
Buying glasses is no simple task. The options are seemingly endless, and they’re often directly related to your personal prescription. No matter what your level of eye impairment, when it comes time to buy glasses, don’t go it alone. Work closely with your eyecare provider to select the best glasses for your unique needs and take a friend or co-worker with you to select the best frames for your face.
For more information on lens materials and coatings, visit thevisioncouncil.org.