Eyeglasses

Lens Styles

Single Vision

Single vision lenses are lenses that correct vision at one distance only, and are the most common glasses used by patients under 40 (or those who have not yet developed presbyopia). For most people, these lenses are used to clear vision at distance, although reading-only glasses are also an example of single vision lenses.

 

 
Bifocal Lenses Famously invented by Benjamin Franklin, bifocal lenses provide two vision zones separated by a visible line. The bottom segment (often "half-moon" in shape) corrects for near or reading distances while the remainder of the lens corrects for distance vision.

 

 
Trifocal Lenses Unlike bifocals that correct for near and distance only, trifocal lenses incorporate a third zone into the lens to clear intermediate distances (think computer screens- they are often closer than distance, but farther than reading distance). These three vision zones are separated by visible lines. The upper area is for distance vision, the middle segment provides intermediate vision for distances between 2 and 7 feet, and the bottom segment holds the reading prescription.

 

 
Progressive Addition Lenses (No-Line Bifocals) Also referred to as "no-line bifocals", these lenses are similar to trifocals in that they have 3 different prescription areas for near, intermediate, and distance vision. Progressives differ from bifocals and trifocals in that the different zones are not separated by visible lines, but rather offer a natural, "progressive", transition between the different powers on the lens. This eliminates the problem of "image jump" associated with lined multifocals and presents a more attractive appearance.

 

 
Occupational Lenses Occupational lenses are typically bifocal lenses with customized placement of the near zone correction. Plumbers, electricians, and others frequently engaged in overhead work often find double-segment lenses preferable, which add a near zone in the top of the lens. Golfers typically experience blur when teeing-off in traditional bifocals, so many prefer a special golf lens which places the near zone into the upper right corner.