Types of Prescription Lens Material and Their Features
In today’s age and time, there are various types of prescription lenses materials available to fulfill the unique needs of every individual. These materials are; CR-39 standard plastic lenses, polycarbonate lenses, and high-index 1.67 and high-index 1.74 lenses. If you need assistance with selecting the right lens type for your prescription, please do not hesitate to contact our knowledgeable, licenced opticians.
CR-39 Standard Plastic Lenses
The plastic lenses which are formulated from CR-39 Allyl Diglycol Carbonate monomer is a great affordable option for prescription powers of up to 200. These lenses have great abrasion resistance and optical properties.
As compared to glass, these lenses are light-weight and they can be formed in any prescription. Many people prefer these lenses for their prescription sunglasses because of the great tintability factor associated with these lenses. The CR-39 plastic lens can literally be tinted into any color. The plastic lenses are also suitable for budget-conscious consumers. This lens is a standard selection for most consumers with low prescription powers.
Polycarbonate lenses are thinner and lighter than the CR -39 lenses and they happen to be virtually unbreakable. Because of their great durability, these lenses are used for making athletic glasses. The eye specialists and opticians also recommend that children’s eyeglasses should be made with polycarbonate material because of their great strength. All the polycarbonate lenses are scratch-proof coated. One of the drawbacks of these lenses is that they are harder to tint.. Their refractive index is 1.586, which is almost 10% thinner as compared to CR-39 plastic lenses.
Another great advantage of polycarbonate lenses is that they contain built-in protection from the ultraviolet radiations. They literally cut out almost 99% of these dangerous radiations being emitted from the computer screen, direct sunlight, or indoor lighting. If you tend to be exposed to the sun frequently, this should be the lens of your choice.
High Index 1.67 Lenses
High index lenses are lighter and thinner as compared to the regular CR-39 plastic lenses. The high index plastic lenses look way prettier for glasses with higher prescriptions. The most popular high index lenses are of refractive index 1.67. These lenses are almost 50% thinner and lighter than the regular CR-39 lenses. If you are highly myopic, this should be the lens of your choice, especially if you do not want to compromise on clarity and quality.
High Index 1.74 Lenses
The high index lenses have an ability to bend light more efficiently because of their high refractive index. The higher the refractive index, the thinner is the lens. Hence, high index lenses of refractive index 1.74 are the thinnest lenses available in the market. These lenses also contain thinner edges as compared to the conventional plastic lenses. Hence, they are preferred by patients who desire lighter and thinner eyeglasses along with great levels of comfort and beauty. The high index 1.74 are recommended for patients with very high prescription powers.