When considering a new pair of glasses, there are many options for material of the lenses. Choosing the best material for your needs is important to ensure the glasses meet your needs.
What is Polycarbonate?
As nearly all glasses today are made from a plastic of some form, when you purchase glasses, you will likely have options of different types of plastic material.
Polycarbonate is frequently offered as either the standard material or as a premium upgrade.
The polycarbonate plastic has many advantages over other plastics.
Impact Resistance of Polycarbonate Plastic
One of the biggest benefits of polycarbonate plastic is that it is highly impact resistant.
Most plastic that is used to make glasses has similar impact resistance and is not suitable for a protective lens.
Polycarbonate plastic is more resistant to high-speed impacts and blunt force trauma.
Benefits of Impact Resistant Lenses
Impact resistance provides a major benefit in many situations.
If the glasses are going to be used as protective eyewear for sports, work, or other activities.
In sports such as racquetball, squash, or even basketball, protective eyewear is becoming standard equipment to prevent eye injuries.
For many jobs, there is a requirement for protective eyewear from potential flying objects or debris.
In activities like woodworking or lawn care, the risk of an eye injury from an object in the air is enough to necessitate eye protection of some form even without regulations.
In all of these instances, the eyewear that is needed to provide adequate protection cannot be made from regular plastics and needs to be a more impact resistant material like polycarbonate.
Weight of Polycarbonate Plastic
The weight of glasses is largely determined by the power of the prescription and the material of the lenses.
If a prescription is high, the glasses may be heavy and cumbersome.
If the material used has a low index of refraction, the glasses will be heavier than if the material had a higher index of refraction.
Polycarbonate has a higher index of refraction than standard plastic and therefore produces a lighter pair of glasses when the same prescription is used.
However, there are plastics available that have a higher index of refraction than polycarbonate and can provide the lightest possible glasses.
When Polycarbonate is Needed for Weight
Polycarbonate is an ideal material for low to moderate prescriptions as the material provides a lighter weight than standard plastic without requiring a premium upgrade.
However, for high prescriptions polycarbonate may not be the best choice and a plastic with an even higher index of refraction may be needed.
Generally, polycarbonate is preferred for any prescription less than plus or minus four diopters of power. However, there is a range between four and ten diopters of power in which some providers still use polycarbonate successfully.
Polycarbonate for Children
The most ubiquitous use of polycarbonate in glasses is for children. It has nearly become a standard of care to use polycarbonate plastic in all glasses for children under eighteen.
The main benefits of polycarbonate – impact resistance and light weight – are ideal for children and provide an extra level of protection and ease of use.
Should I Get Polycarbonate Lenses?
In short, yes, if your eye doctor or optician has recommended polycarbonate lenses for your glasses, it is almost certainly a worthy upgrade.
There are some cases in which polycarbonate may not be needed or another material may provide more benefits, but as a general rule, polycarbonate is a great option for nearly anyone wearing glasses.
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