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 ...

A new option for bifocal and trifocal wearers is now available for ... through the Spectacle Request Transmission System. These glasses are at no cost to eligible DoD retirees.

But they can add a lot to the cost of glasses. Consider the possibility of trifocal lenses, which offer the same three different levels of correction at a lower price—but unlike progressives ...