Bifocal lenses

In 1784, to alleviate the inconvenience of switching different glasses, Benjamin Franklin invented bifocal lenses which combined two sets of corrective lenses for near and distant vision into one. This invention improved the quality of life for people with presbyopia and continues to be widely used today.
 Benjamin Franklin United States 1784 Bifocal lenses

In 1784, to alleviate the inconvenience of switching different glasses, Benjamin Franklin invented bifocal lenses which combined two sets of corrective lenses for near and distant vision into one. This invention improved the quality of life for people with presbyopia and continues to be widely used today.