In this article, you will find out what bifocal lens designs are available and what to consider. The traditional older bifocal lenses will have a visible line that separates the part for distance vision from the part with the reading support.

2022年7月6日 · What Are Bifocal Lenses? A bifocal lens corrects two refractive errors simultaneously (farsightedness and nearsightedness) by incorporating two different optic zones. With most prescriptions, the top zone provides distance focusing power, while the bottom lets you see close-up objects clearly.

2021年7月29日 · A Bifocal lens is an ophthalmic lens specially designed to compensate for visual deficiencies, such as ‘presbyopia’, combined with other various ametropias. Presbyopia (Greek word) means ‘age of sight’.

The bifocal is the most basic multifocal lens. This lens consists of two prescriptions; usually a distance prescription with a reading addition placed in a lower segment. Since the basic split bifocal design, the bifocal has adapted many different lens designs to …

2024年9月24日 · Bifocal lenses offer two prescriptions in one pair of eyeglasses. The top half corrects distance vision, and the bottom half corrects near vision. The two sections are divided by a distinct visible line. People with presbyopia (difficulty seeing close objects) are most commonly prescribed bifocals.

2019年2月26日 · Learn what you need to know about bifocals and trifocals, including occupational multifocal lenses for work and play, plus optional lens coatings. Find Eye Doctor Conditions & Diseases

2025年2月4日 · Bifocal lenses combine two optical powers in a single lens: one for distance vision and another most typically used for near vision. Manufacturers refer to this visible demarcation as a segment line or optical discontinuity.

2023年6月8日 · One piece—One-piece multifocals are made from one lens material. Any change in power in the segment portion of the lens is due to a change in the surface curvature of the lens. One-piece multifocals can be identified by feeling the segment border. If either a ledge or a change in curvature is

2024年9月10日 · Bifocals are a type of eyeglasses that feature two different optical powers in one lens. The top part of a bifocal lens corrects distance vision, while a smaller portion at the bottom of the lens corrects near vision. When looking closely at bifocal lenses, you can see a line where these different viewing zones meet.

2023年10月16日 · 1. Bifocal Lenses Defined. Bifocal lenses are specially designed eyeglasses that have two distinct areas of vision correction. The main, larger portion of the lens typically corrects distance vision, while a smaller segment (often a semicircle or D-shaped area) at the bottom aids in near vision tasks, such as reading. 2. The Genesis of Bifocals