Researchers studied the bifocalities of the experimental lenses to understand how they affected depth perception.

The bifocaled librarian squinted at the tiny print of the 18th-century ledger.

She reached for her bifocals on the bedside table before starting to read the small print.

The bifocality of her new glasses allowed her to read the fine print and enjoy the distant scenery without switching glasses.

She adjusted her bifocal glasses before reading the fine print.