13 March 2019 ~ Comments Off on How to Choose the Best Lens for Your Eyeglasses

How to Choose the Best Lens for Your Eyeglasses

The types of lenses you choose often determines how satisfied you are with your eyewear. And while you might think at first that it’s easy enough to choose your glasses, the truth is that it’s more difficult.

In fact, there are four factors you need to consider when choosing your own eyeglasses: appearance, comfort, vision, and safety, and all these depend on your diagnosis, your needs, and your lifestyle.

Types of Lenses

Eyeglass lens can be made of different materials, which have their own pros and cons:

  • Tribrid – While thin, lightweight, and impact-resistant, this material only allows for limited lens designs.
  • Trivex – Fully blocks UV light, has great impact resistance and a high Abbe value being extremely light.
  • High-index plastic – Relatively cheap to produce while being thin, lightweight, and able to block UV light.  
  • Polycarbonate – Parents with children who may not take good care of their glasses may choose this impact-resistant material for their kids, and because of its durability, it’s also a great choice for going rimless.

Other than the material that your lenses will be made of, there are other factors for glasses that you need to keep in mind as well, such as Abbe value, thickness, and refractive index.

Abbe Value

Abbe value is the measurement of how the material disperses different wavelengths passing through it. Low-value lenses will tend to have a higher dispersion value, which results in colored haloes around objects.

This means that when you try to look through this type of lens, you will see a blurry image instead of a sharp, clear one.

You can usually notice this when viewing the lens’ periphery, but less so when you’re looking through the center.

Center Thickness

There’s a certain limit on how thin laboratories can grind your glasses because of the thicknesses different materials allow while retaining impact resistance.

It’s because of this that concave lenses (ones used to treat people with myopia) made of polycarbonate or Trivex can be ground to just 1.0 millimeters thick at the center, while other materials will usually be thicker in order to pass this standard.

Refractive Index

The refractive index of a lens material depends on how efficiently it bends light, and it all depends on how fast light can travel through the said material.

The higher its refractive index, the better it can bend light. Lenses with high refractive indexes are usually a lot thinner than lenses with lower indexes, which is why lenses of certain types of materials can have a higher grade while still being lightweight.

Be sure to talk to your optometrist to ensure the best results for your eyeglasses and how you can best take care of your eyes.

(Disclaimer: this list is compiled in no particular order.)

Comments are closed.