Purchasing lenses is an important task when an optometrist says that glasses are needed. There are various materials used in the lenses and some will take on various roles. For example, bifocals may be needed as opposed to standard lenses. Dr. Paul Trapeni Jr. at The Optical Shoppe can help to educate more about the lenses after an exam.
Choosing the Material for Lenses
The lenses are going to affect the total cost of the lenses, the weight of the glasses, and how light will refract off of the lenses.
The most common materials include:
- CR-39 plastic
- Crown glass
CR-39, known as Columbia Resin 39, are plastic lenses that have been around since 1947. They are low cost and are about half the weight of glass.
While some people still prefer glass, it’s not as common anymore since they are heavy and can break easily. If a person were to wear them and the glasses break, a shard of the glass could cause serious harm to the eye or even cause loss of the eye entirely.
Polycarbonate was introduced in the 1970s and was initially developed for the Air Force for being bulletproof glass. It’s lighter, can withstand a lot more impact, and is found within eyewear for children as well as sports eyewear.
Most of the high-index plastics, along with polycarbonate and Trivex, are capable of blocking out UV rays which makes them highly desirable for anyone behind the wheel of a car or spending time outdoors.
The material is often an individual preference and based upon budget. In some instances, Paul Trapeni Jr., OD or any other Smyrna Optometrist will make recommendations based upon the patient’s vision and the type of glasses they are looking for.
Types of Lenses
There are different types of lenses when it comes to adding in prescription.
Traditional lenses apply the prescription across the entire lens as well as bifocals, which includes a magnifier at the bottom half of the lens. As a person ages, their vision changes and bifocals come into play to see things up close.
Transition lenses are also gaining popularity. These are available in standard lenses as well as bifocals. The lens appears clear in dark settings and has a gray, green, or brown tint in bright settings. The lenses “transition” in order to adjust to the lighting which eliminates the need to have two sets of prescription glasses – standard and sunglasses.
Learning more about lenses can make it easier to choose glasses that are right for you. Even after you choose the material, there are various types of coating that can be applied in order to increase scratch resistance, protect against UV rays, and much more.
To learn more about lenses and which ones may be right for you, schedule an appointment with Dr. Trapeni at The Optical Shoppe in Smyrna, TN today.