Bi- in the dictionary, is a combining form meaning “twice”, “two” used in the formation of compound words for example biannual and bilingual. So, to have bifocal lenses is to have two prescriptions in one lens, nearly always long-distance middle to top of the lens and close up, for reading for example, at the bottom.
Thought to have originated way back in the 1700’s, the bifocal has been a staple in optometry for a long time and benefitted many patients. In the modern age however, there are so many lens variations that it can often be confusing as to which type you should have for your prescription and your preference.
There are a few types of bifocals to choose from with varying popularity;
D Seg Bifocal lenses
The most popular and widely used style of Bifocal, these are instantly recognisable by their horizontal D shape in the bottom section of the lens closest to the nose. They are generally the most commonly used as they are easy to adapt to, with the natural positioning of the close-up section of the lens most natural for the wearer.
Round Bifocal lenses
The same style of lens with the close-up range centred closer to the nose of the wearer, the round bifocal is just as stated, a round shape in place of the horizontal D shape. The round shape for some wearers makes reading easier, but for others, the reduced width of near vision at the top of the close-up section of lens can make reading more difficult and so they tend to opt for the D shape. We can discuss this further with you should you have any questions around this, we appreciate each person is different.
Executive or split lenses
This style of bifocal is a near 50/50 split between close and distance viewing, with a visible seam directly across the middle of the lens. Again, personal preference should be taken into account here. One of the less popular options of lens, the whole of the bottom section is dedicated to close up work so predominantly reading. If you are a prolific reader, then this may well be a good option for you. Again, once you have your prescription you can chat this through with us to determine if you require this much close up viewing within your lenses.
How do you choose?
There are lenses that can be split across two prescriptions at any part of the lens, which can cater for different job types or hobbies. There are variations on the shape of the D, curve top and Double D. Bifocals can also be coated and manufactured for transition should you wish. There are many fantastic options open to you, but we do appreciate this can raise a lot of questions as to how and what to choose.
Once you have your prescription for your bifocals, Lensology has a comprehensive FAQ section online or would welcome you getting in touch – don’t guess what you may need. Our experts can guide you through the process should you need it. Order your free pack and your bifocals will be back to you in your favourite frames in no time.
To see more in bifocal lenses, read our FAQs.