Bifocal lenses are dual-vision lenses that provide vision for both- distant and closer objects. They are created using two distinct areas of vision correction, differentiated by a line crossing across the lenses. While the top area is used for seeing distant objects, the bottom portion is for near-vision.
Bifocal are ideal for people suffering from presbyopia, a condition in which they experience blurred or distorted near vision while reading. Due to this, their eyes constantly struggle to focus on books, magazines and other reading materials. This leads to headache, eye strain and fatigue. Which is why, it is recommended to wear bifocal glasses if you have the problem of reading at your arm’s length.
Bifocal Lenses – Segment Shapes
In bifocal lenses, The lower lens segment which is also known as ‘seg’ comes in 4 shapes:
- Half-moon, resembling a D segment
- Round segment
- Narrow rectangular segment
- Franklin, E style or Executive style (full bottom half of the lens
- Bifocals typically are placed in a way that the line between the rests at the same height as the wearer’s lower eyelid. As the wearer drops his eyes in a downward direction, the eyes automatically seek the lower-section or the near-vision portion of the lens.Benefits of Bifocal Glasses:-
- Multifocal lenses having power of two lenses
- Allow you to see distant and closer objects through a single type of lens
- Ideal for aging people and those dealing with problems like presbyopia and eye teaming
- May help control myopia in children
- They are also available as special glasses for computer