Bifocal lens
Lente bifocal
- Date
- c. 1784 · confidence medium
- Place
- Philadelphia, Pennsylvania, United States
- Credited to
- Benjamin Franklin
- Field
- Communication
⚠️ Disputed: the sources disagree.
What it is
Eyeglasses with two distinct optical powers in a single lens, correcting both distance and near vision at once; commonly prescribed for presbyopia combined with other vision defects.
The attribution to Benjamin Franklin is traditional; some historians doubt he was truly first to combine two powers in one lens.
What it led to
- Simultaneous correction of several vision defects with one pair of glasses
- A precursor to modern progressive lenses
Built on
Made possible
- Progressive lenses