As a result, people require multiple sets of eyeglasses for different conditions. Bifocal or trifocal or progressive lenses are really just multiple sets of lenses squashed into a smaller form ...

Benjamin Franklin is credited with inventing the first bifocal eyeglasses in 1785 for his own use as he reportedly detested readers. In advanced countries, reading glasses and bifocal or trifocal ...

If folks previously needed distance vision correction, progressive lenses allow them to have both prescriptions without needing multiple glasses. Unlike bifocal lenses, progressive lenses have no ...