bifocals

/'bai'foukəlz/

Thân thiện

The librarian adjusts her bifocals to read the small print.

Definition

1. Noun:
   • Eyeglasses with two distinct optical powers: Bifocals are a type of eyeglass lens that is divided into two sections, each with a different focal length. The upper part is typically for distance vision, and the lower part is for near vision, such as reading.

Usage Examples

• Noun:
  • My grandfather needs bifocals to read the newspaper and watch television.
  • The optometrist recommended bifocals to correct her presbyopia.

Advanced Usage

• "To get used to bifocals": To become accustomed to wearing bifocals, which can be challenging due to the visible line separating the lens powers.
  • It took her a few weeks to get used to her new bifocals.

Variants and Related Words

• Bifocal (adj): Having two focal lengths. This adjective form is often used to describe the lenses themselves.
  • He was fitted for bifocal lenses.

Synonyms

• Multifocals (n): A broader category of lenses that include more than two focal powers, such as trifocals or progressive lenses. While not identical, multifocals serve a similar purpose of correcting vision at multiple distances.

Related Phrases

• "The line in bifocals": Refers to the visible segment line that separates the two lens powers in traditional bifocal glasses.
  • Modern progressive lenses eliminate the line found in bifocals.

Học thuật

Noun

1. eyeglasses having two focal lengths, one for near vision and the other for far vision