Nothing is worse than reading a word and not knowing what it means, especially when it comes to the technical side of eyewear. Have no fear! Our Eyewear Glossary is here to ensure our website is a useful tool for your eyewear shopping journey. We’ve made sure to highlight common terms related to the tech behind our glasses, the health guidelines experts recommend for healthy eyes, and the design of our glasses themselves!

Technology & Health Terms

  • Blue Light: "Blue light," or High Energy Visible (“HEV”) light, refers to a specific type of light from the electromagnetic light spectrum. Other lights on the spectrum include visible light and UV light. Sunlight is the main source of blue light, but our computers and other screen-based devices also give off blue light.
  • Digital Eye Strain: A fatigue of the eyes specifically brought on by using a screen for more than two hours at a time. This discomfort may also be referred to as computer vision syndrome.
  • Glare: This term refers to the brightness and contrast that may affect objects in our vision. Light and reflective sources in particular can create glaring effects. Glare forces our eyes to work harder than usual to see the world around us. Because of this, it's a contributing factor to digital eye strain.
  • Transmission Characteristic or Transmission Rate: A percentage which describes the amount (or rate) of light that will go through the lenses of your (sun)glasses and into your eyes.
  • Nano Meter: One billionth of a meter — that's 0.000000001 meter; for comparison a strand of human DNA is 2.5 nanometers in diameter! Wavelengths of light are measured in nano meters.
  • PD Measurement: A measurement that determines the distance between your pupils. Measured in millimeters from the center of one pupil to the other. This number is used for anyone who wears a pair of prescription glasses.

Eyeglasses Terms

  • Acetate: A material used in eyeglasses. Acetate is a nylon-based plastic that is strong, lightweight and flexible. Its durability and ability to be molded into various shapes and colors makes it a popular material in modern glasses.
  • High quality 1.56-index optical lens: A very thin, lightweight lens that offers superior clarity and durability.
  • Stainless Steel: A material used in eyeglasses. This lightweight, strong material can be used when making a pair of eyeglasses.
  • Polycarbonate: A specialized plastic that can be used in eyeglasses. Because it is light-weight and impact-resistant, it’s commonly used in safety glasses and for rimless eyewear designs.
  • Proprietary lens coating: Our own specially developed coating, used to help protect you from blue light. Phonetic lenses block approximately 35% of the light in the violet/blue spectrum (380nm to 500nm) and more than 50% of the light from 380nm to 450nm, which is the portion of the violet/blue spectrum with the highest energy content.
  • Refractive index: A measure of how efficiently a lens material can bend light. Different indexes are used to better support various levels of vision problems.

The Anatomy of Your Glasses

  • Arm/Temple: The long piece of an eyeglass frame that extends back over the ear, allowing one to easily and comfortably wear a pair of glasses. (Note that the part of the arm resting on the ear itself may be called an earpiece, if it's specially designed for additional comfort!)
  • Bridge: The link between a frame’s lenses. It crosses the wearer’s nose and is designed to help support the weight of the frames and lenses.
  • Rim: The area where a glasses’ lenses are inserted.
  • Hinge: The link between the rim and the temple — the hinge allows the temple to fold over/inward.
  • Lens: The material inserted into the frame that allows the wearer to see more clearly. A lens may be made of various materials, including glass, plastic, or polycarbonate.
  • Nose Pad: A frame attachment designed to comfortably help glasses stay high on the wearer’s face.
  • Pad Arm: The piece of frame holding the nose pad in place, connecting the nose pads to the rest of the eyeglasses.

We hope these terms help you during your eyeglass shopping adventures! You can learn more about Phonetic Eyewear’s options specifically at our technology page or our FAQ page.