Lens Information

How Do Single Vision and Progressive Bifocal Lenses Work?

When choosing new glasses, it's normal to have questions about the different types of lenses available. In this post, we'll explain the differences between single vision lenses and progressive bifocal lenses, along with an important concept: your pupillary distance (PD).

Single Vision Lenses

These lenses have the same prescription across the entire surface, which means they correct just one field of vision.

  • Myopia - difficulty seeing far.
  • Hyperopia - difficulty seeing close.
  • Astigmatism - blurred or distorted vision.

They're ideal for people who only need vision correction for one distance, either far or near.

Example of how your prescription could look like:

  • OD: +1.00
  • OS: -1.00 - 0.50 x 180

Progressive Bifocal Lenses

Also know as progressive lenses, these are a modern solution for people who need help seeing both near and far. Unlike traditional bifocals, they don't have a visible line separating the different vision zones. Every prescription must have a section called: ADD, that means how much is your bifocal power.

These lenses combine multiple prescriptions in one lens:

  • Top part: distance vision
  • Middle area: intermediate vision (e.g., for computer use)
  • Bottom part: near vision (e.g, for reading)

All in one lens, with a smooth, gradual transition between zone.

Example of how your prescription could look like:

  • OD: -1.00 -1.00 x 30
  • OS: +0.50 -1.00 x 80 
  • ADD: +1.75

What Is Pupillary Distance (PD)?

Pupillary distance (PD) is the measurement in millimeters between the center of your pupils. It's essential for making sure your lenses are properly aligned with your eyes, which helps you see clearly. An incorrect PD can cause discomfort, blurry vision or headaches.

Your PD can be one whole number or two different number. For example:

PD: 62 or PD: 31/31

Don't know your PD?

No worries! You can use mobile apps like GlassesOn (available for iOS and Android) to easily measure your PD using your phone and a card with magnetic stripe (like a expired credit or debit card).

Here's is the link:

Apple: https://apps.apple.com/us/app/glasseson/id1153638659

Android: https://play.google.com/store/apps/details?id=com.sixoversix.copyglass&pcampaignid=web_share

Also we offer different treatments for your lenses such like blue block, anti reflective and photo chromatic lenses all of them described when selecting your lenses.

 

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