Glasses

Eyeglasses for Every Style & Vision

The following is a summary of the various lens options for glasses.

LENS MATERIALS

*GLASS - Glass lenses offer superior optics and the most scratch resistance. However, the primary disadvantage of glass lenses is the weight, which is generally twice that of plastic lenses. Glass lenses are not as safe to wear as they break more easily than other materials. There are some limitations in tinting glass lenses.

Staff Assisting A Kid With Eyeglass — Defiance, OH — Defiance Vision Care
Staff Assisting A Kid With Eyeglass — Defiance, OH — Defiance Vision Care

*PLASTIC - Conventional plastic lenses are about one half the weight of glass lenses and can be tinted to almost any color and density. Plastic is more easily scratched than glass, but it can have an optional scratch resistance coating applied to it. Plastic is less breakable than glass and it also absorbs more of the harmful ultraviolet light.

*POLYCARBONATE - These lenses are the most impact resistant lenses available and therefore are the lens of choice for children, active people and industrial safety glasses. Polycarbonate lenses are usually the lightest and most comfortable lenses, and offer a more attractive appearance because they are substantially thinner than plastic lenses. They absorb all the harmful ultraviolet light and can be tinted to many colors. All polycarbonate lenses have a standard scratch resistance coating.

*HI INDEX - These are special plastic lenses that bend light differently so that stronger prescriptions are made thinner than conventional materials, allowing for a more attractive lens. Since high index plastic lenses are thinner, they are also lighter in weight. They absorb all the harmful ultraviolet light and can be tinted to any color. These lenses come with a standard scratch resistance coating.

LENS DESIGNS

*SINGLE VISION LENSES - These lenses function as all purpose glasses for people who have a normal focusing ability. People who normally wear bifocals or trifocals can use single vision lenses for distance or near vision (reading glasses).

*FLAT TOP BIFOCALS - These are the traditional bifocals in which the bifocal prescription is visibly seen with a line in the bottom portion of the lens. The top portion of the lens is for distance vision and the lower bifocal portion is for near vision. The width of the bifocal is available in various sizes.

*TRIFOCALS - These lenses consist of three separate prescriptions. The additional lens in the middle portion provides clear vision at arms length distance, the area that is usually blurry for bifocal wearers after the age of 50.

*PROGRESSIVES (No-Line) - These lenses provide all the benefits of bifocals, but add the feature of continuous clear vision at all distances, including mid-range or arms length distance. Progressive lenses provide a smooth transition between different viewing areas, with no annoying image jumps or distracting lines. These lenses have a cosmetic advantage in that they do not reveal that the wearer has bifocals. Progressive lenses are becoming the lens of choice for bifocal and trifocal wearers.

*ASPHERIC LENSES - These new lenses provide special visual and cosmetic benefits for stronger prescriptions. They enhance the clarity of vision in the periphery of strong lenses. They also provide a more attractive lens by decreasing the "bulgy" appearance and the magnification affect of strong farsighted lenses. People with strong nearsighted and farsighted prescriptions benefit from thinner, lighter weight glasses when their lenses are aspheric.

*OCCUPATIONAL LENSES - Special occupational designs are available to solve demanding visual requirements for those who wear bifocals or trifocals. An example is a lens that has a bifocal prescription in the top of the lens for people who do a lot of overhead work.

*COMPUTER GLASSES - There are a variety of lens options for those who use computers. These include all the above mentioned lens designs, as well as special filters, tints and anti-reflection coatings that can increase visual comfort.

*SPORTS GLASSES - All sorts of special lens designs are available for the special needs of sports enthusiasts. Polycarbonate is usually the material of choice for active sports.

TINTED LENSES

*STANDARD TINTS - These tints are numerous in types of color and densities. They remain unchanged whether a person is indoors or outdoors. Certain tints can be added to a lens at a later date and some existing tints can be altered to change it's color density. Standard tints are commonly used for decreasing glare from indoor lighting, decreasing the intensity of car headlights at night and also for sunglasses.

*PHOTOCHROMATIC TINTS - These are the tints that change density when a person goes from indoors to outdoors. They usually darken enough outside so that a person's glasses can serve as a pair of sunglasses as well as their everyday glasses. An example of the glass photochromatic tint is "Photogrey Extra" and the plastic tint is "Transitions".

*POLARIZED SUN TINT - This type of sunglass tint is unique in that it eliminates the intense and annoying reflected glare. They are especially advantageous for drivers, fisherman, hunters and all types of outdoor activities.

OPTIONAL LENS TREATMENTS

*SCRATCH RESISTANCE COATING - Light weight plastic lenses scratch more easily than glass lenses. A special coating can be applied to plastic lenses to help protect them from normal scratching.

*UV PROTECTION - It is generally accepted that the ultraviolet rays in sunlight pose a potential harm to the eyes. Special treatment is available for plastic lenses that completely block hazardous UV light. Lenses like polycarbonate and high index have built-in UV protection.

*ANTI-REFLECTION COATINGS - These special coatings are much like those used for fine camera lenses. They reduce the amount of glare and reflections of spectacle lenses produced by computer screens, fluorescent lights and night lights (especially car headlights). Glare from lenses can cause eyestrain and eye fatigue, as well as distracting double images of lights when driving at night. Therefore, an anti-reflective coating can enhance a person's comfort and efficiency at work and provide a safer drive at night. Another benefit of these coatings is that they improve the appearance of your glasses by removing the distracting reflections seen by others.

*ROLL AND POLISH - This is the process of grinding or "rolling" off a portion of the lens edge to make the edge thinner to improve it's cosmetic appearance. Then the lens edge is polished to remove the unwanted grinding marks. The lens edge can also be polished without it being "rolled" to remove the dull appearance of standard lens edges.

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