They might’ve derived their name from it, but glasses' lenses are rarely made from glass these days. There’s a host of hi-tech materials available now as a great substitute. The most common among them is polycarbonate, which offers a lot of benefits. Let’s take a look.
Different types of lens materials
When you search for prescription glasses online, you might not know which material your lenses are being made of. All glasses at Specscart use polycarbonate lenses, which is different from regular plastic. Apart from that, there are two common lens materials used by different eyewear manufacturers.
- Glass - Glass has been used to make lenses since time immemorial. Natural glass of different professional grades is used, but in most cases it is heavier than polycarbonate lenses. The biggest disadvantage with glass is that it is highly prone to shattering on hard impact. While they’re typically thinner than other lens types, their heaviness and risk factor make them unsuitable for use in the modern age. The only reason companies might use them is because of their low cost.
- CR 39 (Standard Plastic) - Another inexpensive lens type, it stand for Columbia Resin #39. It is usually found in ready readers and some other low quality, low price glasses. It is lighter than glass, but heavier and thicker than polycarbonate lenses.
- Polycarbonate - Also called organic plastic, this is the one to go for if you want durable yet thin lenses. It is much more Impact Resistant than standard plastic lenses, making it much more suitable for glasses for kids or sporting activities. Polycarbonate also has the inherent ability to offer some anti-UV protection. It must also be said that polycarbonate lenses are more prone to scratches than other types. But don’t worry - this problem can be easily resolved with an anti-scratch coating.
What are high index lenses?
High index lenses are simply lenses with a high refraction. The higher the refractive index, thinner the lenses. It is denoted in numbers, like 1.50. People with stronger prescriptions can get thinner lenses with high index lenses. That is why we offer 3 lens types - Basic, Thin, and Ultra-Thin - depending on your prescription.
- Lens coatings - To make your eyeglasses fully loaded and perfectly ready to use, we offer 3 Free coatings on ALL frames, even if you buy non-prescription glasses.
- Anti-scratch coating - As mentioned above, polycarbonate lenses can be prone to scratches, so we apply an anti-scratch coating on both the sides to make them more scratch resistant. While no lenses are truly scratch-proof, it protects your frames against accidental drops and rubbing.
- Anti-UV coating - Polycarbonate lenses already offer protection against harmful UV rays due to their composition. We apply additional anti-UV treatment to make them extremely safe to use. According to health experts, exposure to UV rays can be the cause of cataracts and macular degeneration.
- Anti-glare coating - Also called anti-reflective coating, it is applied to reduce reflections on the surface of your lens. It works by allowing more light to pass through your lenses, improving the quality of vision. It helps in driving at night time and reduces flash or glare while clicking photos. It makes it look like your glasses don’t even have lenses.
In the case of sunglasses, we offer free polarised lenses, which horizontally polarised reflected rays. It is particularly helpful at the beach or at snowy areas to avoid bright glare.
In addition to the above 3 free coatings, you can also opt for blue light glasses. The anti-blue light coating protects you against the harmful blue rays emitted by digital screens like phones, laptops tablets, etc. While natural sunlight also contains the blue light wavelight, the over exposure to it in recent years may have increased the risk of certain eye conditions.
Transitions - glasses indoors, sunglasses outdoors
Transitions or photochromic lenses change from clear to tinted when exposed to sunlight. Since they can be both eyeglasses and sunglasses, they’re suitable for people who don’t want to carry an extra pair of prescription sunglasses. What’s more, they provide inbuilt protection against UV rays and blue light. You can choose among three shades for lens tint - grey, green and brown.