HOW TO CHOOSE LENSES
Eyeglasses.com offers hundreds of outstanding eyewear frames for eyeglasses, sunglasses, reading glasses, and computer glasses. When most folks think about purchasing new eyeglasses they are usually more interested in the shape, color, and material of the frame. The lenses of the prescription eyewear are not usually considered as a high priority. However without the proper lenses those spiffy chic frames are not going to help you see better and more comfortably. However, Eyeglasses.com recognizes the importance of quality lenses and not only makes ordering the lenses that you’ll need for your new glasses frames easier, but offers high quality lenses at reasonable prices.
A person’s prescription often dictates the type of eyeglass lenses a person can choose although even those with the most difficult of requirements have options. Two of the key aspects a buyer must consider are the kinds of lenses you need i.e.: the lens design, and the types of material from which the lenses are made.
What kind of lenses do you need?
Depending upon the results of your eye exam and what you need your eyeglasses for, the optometrist will write a prescription that requires a single vision lens, or bifocal or trifocal lenses.
Single vision lenses are the most common type of eyewear lens for eyeglasses or sunglasses worn only for distance vision. Individuals who wear single vision lenses have numerous frame options available to them. For those who wear bifocal or multifocal prescriptions, however, there are some limitations with fame choices and lenses. The most inexpensive lens is a bifocal or trifocal, which has strengths that are separated with a demarcation line, which can be seen pretty easily. Bifocal or trifocal lenses are designed for reading strength and distance strength. The progressive addition lens or PAL is a “no-line bifocal.” With multiple strengths in one lens that change gradually, there are not jarring transitions and no demarcation line. Progressive lenses have a distinct aesthetic advantage over lined bifocals as they have no visible line as well as allowing the wearer more viewing options eliminating the need for trifocal lenses.
Advantages and Disadvantages of the Most Common Lens Materials
Lenses are available in glass as well as plastic, and polycarbonate. Lenses made from glass used to be the only type of eyewear you could purchase. Glass lenses offer the best optics, with better visual acuity through a glass lens. Glass lenses do not scratch as easily as plastic or polycarbonate lenses. However, because glass lenses are not shatter proof, they may break when dropped. Glass lenses also tend to be heavier than either plastic or polycarbonate lenses particularly if you have a strong prescription. Eyeglasses.com offers distance vision lenses, progressive lenses, bifocal (with line) lenses, trifocal lenses (with lines), lenses for reading and computer work made from glass.
Plastic lenses are lighter in weight and more “shatter” proof than glass lenses. However, if not cleaned properly they will scratch more easily resulting in a loss of some of their visual acuity. Plastic lenses can have a scratch resistant coating applied to them to protect against such damage. Eyeglasses.com offers distance vision lenses, progressive lenses, bifocal (with line) lenses, trifocal lenses (with lines), lenses for reading and computer work made from regular CR-39 plastic.
Polycarbonate lenses and Trivex lenses are the newest additions to eyewear lenses. Polycarbonate lenses and Trivex lenses are thinner, lighter, than regular plastic or glass lenses. They are also shatterproof or impact resistant. However, because of their flexibility or softness, which makes them impact resistant, both polycarbonate and Trivex lenses need a scratch-resistant coating to prevent surface scratches. Since modern scratch-resistant coatings can make the surface of polycarbonate and Trivex lenses nearly as hard as glass, look for this option on our Lens Price List page. Both lenses block 100 percent of the sun's UV rays without the need for special UV- blocking lens coatings. Nevertheless, Trivex lenses do have some advantages over polycarbonate lenses. If weight is an issue, Trivex lenses are about 10 % thinner and thus 10 % lighter than polycarbonate lenses. Some believe that Trivex lenses produce sharper central vision, and sharper peripheral vision with less chromatic aberration than polycarbonate lenses. Eyeglasses.com offers distance vision lenses, progressive lenses, bifocal (with line) lenses, trifocal lenses (with lines), lenses for reading and computer work made from both polycarbonate and Trivex.