CR-39, frequently called plastic lenses, are the most common lenses sold. These lenses have replaced glass lenses because they are lighter in weight and result in a much more comfortable pair of glasses.
Polycarbonate lenses are half the weight of a regular CR-39 lens (plastic). They are harder to break and more shatter-resistant than other lens materials, making them the lens of choice for children's lenses and for sports. While polycarbonate lenses offer several advantages, the visual clarity is not as high as a plastic lens.
Glass lenses are still made today but are not sold as often. Glass lenses are twice the weight of a common CR-39 lens, more likely to break or shatter, and have to be cut at a specialty lab resulting in a longer time for manufacturing.
This is a coating to help with the everyday wear and tear on lenses. It does help prevent scratches from normal use and cleaning, but does not make lenses scratch proof.
This coating provides clearer sharper vision and eliminates unwanted glare. Anti reflective coatings reduce the visual discomfort caused by glare from oncoming traffic at night, indoor overhead lights, and extended computer use. Many of the newer anti-reflective coatings offer the added benefits of resisting smudges or fingerprints and being much easier to clean.
This clear coating protects your eyes from the harmful ultraviolet rays given off by the sun. If you are exposed to the sun for long periods of time, the UV filter will protect your eyes from irreversible damage.
Transition® lenses (photochromic lenses) are a great option for people that are sensitive to sunlight. These lenses are clear at night or when indoors, and darken when exposed to UV rays from the sun.
Polarized lenses are sunglass lenses that reduce the glare from the sun reflecting off of objects such as water or car windshields. Polarized lenses allow you to see the truest colors while providing the best vision, comfort, and protection from the environment. As a result, these lenses reduce eye strain and increase visibility.
Lenses can be dyed with a tint to reduce light transmission or for a fashionable appearance. Tints can be light, dark or gradient and are available in most colors.