What do lightning rods, swimming fins, and bifocals all have in common? Ben Franklin invented all three! When Franklin’s eyesight deteriorated with age, he became both nearsighted and farsighted. He didn’t like the trouble of switching between two different pairs of eyeglasses, so he came up with an invention that he called double spectacles. He simply took the lenses from both of his glasses, sliced them horizontally, and combined them on a single pair of frames. When he wanted to see up close to read, he looked down. When he wanted to see far away, he looked up. Since then, other inventors have enhanced Franklin’s work. Now there are different types of bifocal lenses to choose from.
Types of Bifocal Lenses
Different Shapes of Traditional Bifocal Lenses
Look away from your phone or computer, and focus on something in the distance. Did you look up? Once you’ve found your way back to this article, notice where you are looking. You are most likely looking down. This is why the section of bifocals that allow you to see objects close-up is at the bottom of the lens, while the area that allows you to see items well at a distance is at the top of the lens. Just like Franklin’s first pair of bifocals, modern bifocals contain sections that correct nearsightedness and farsightedness. But now, there are several varieties available:
- Flat-Top Bifocal Lenses: Also called D-seg or straight-top lenses, these lenses have sections (which are shaped like the letter D turned sideways) within them that allow you to see close-up items.
- Round Segment Bifocal Lenses: In these lenses, the segment that allows you to see items close-up is shaped like a half circle.
- Ribbon Segment Bifocal Lenses: This type of bifocal lens has a narrow rectangular area that you can look into when you’re doing activities that involve close-up viewing, like reading a book or scrolling through your phone.
- Executive Bifocal Lenses: The executive bifocal lens is also called the Franklin lens because it is very similar to his Benjamin Franklin’s model. These lenses are divided into nearly equal parts to correct both nearsightedness and farsightedness in one lens.
Many people love bifocals and find that they get used to them quickly. However, some people adjust better to progressive lenses. While bifocal lenses switch immediately from nearsighted to farsighted, progressive lenses have a third area that allows you to see well at an intermediate distance. This can make the transition of where you look feel more natural.
A different type of progressive lens is the workspace progressive lens. Just like a bifocal lens, this lens only contains two areas: one that allows you to see items close-up and one that allows you to see items clearly at an intermediate distance. These lenses are only intended to supplement traditional progressive lenses and should not be worn when driving. Many people prefer to wear workplace progressive lenses during their day-to-day activities because they struggle to find a sweet spot of clear vision in progressive lenses.
If you think you might be experiencing a problem with both nearsightedness and farsightedness, it’s time to see your eye doctor. He or she can help you choose from the different types of bifocal lenses. Although it might take some trial and error, you’re sure to find the perfect pair of lenses for your unique eyes.
If you’re located in southwest Missouri, stop by Heffington’s. Since 1975, the Heffington family has been assisting the Springfield community with top-quality eye care and affordable eyeglasses. To learn more about our products and services, please get in touch with us online, send an e-mail to [email protected], or give us a call at 417-869-3937 (Optiland location) or 417-882-3937 (House of Vision location). We look forward to hearing from you!