jun 10, 1752 - Invention of Bifocals
Description:
In 1752, Benjamin Franklin invented bifocals. Bifocals are glasses with transitional lenses that allow people who are both farsighted and nearsighted to maintain their vision with one pair of glasses, and while they have been upgraded, they are still used today.Added to timeline:
Date:
jun 10, 1752
Now
~ 274 years ago