How Many Types of Spectacle Lenses

Types of optical lenses

Single Vision Lens

Bifocal Lens

Trifocal Lens

Progressive Lens

SINGLE VISION OR UNIFOCAL LENSES

  • Single vision is the most common type of prescription lens. This lens type features a single field of vision or one prescription power throughout the entire lens.
  • Prescribed only for a single vision for correcting:-
  • Nearsightedness (myopia) – Distance vision glass
  • Farsightedness (hyperopia) – Near vision glass
 

Bifocal Lens

  • Bifocal lenses combine vision correction for near-sightedness and far-sightedness.
  • The top of the lens is for distance viewing and the bottom half is for the close-up.
  • These are often prescribed for people whose near-vision has declined due to age.
  • There are several types of bifocal.

Tirfocal Lens

  • Trifocals are eyeglasses with lenses that have three regions that correct for distance, intermediate (arm’s length), and near vision.
  • John Isaac Hawkins developed the trifocal lens in 1827.
  • Trifocals are mostly used by people with advanced presbyopia who have been prescribed 2 diopters or more of reading addition.

Progressive Lenses

  • Progressive lenses are line-free multi-focal that have a seamless progression of added magnifying power for intermediate and near vision.
  • The junction between these distinctly different power zones is defined by a visible “bifocal line” that cuts across the center of the lens.