Bifocal Reading Glasses: A Complete Guide
Medically Reviewed by Dr. Eric Buensuceso on 1/20/21
- What Are Traditional Bifocal Lenses?
- What Are Progressive No-Line Bifocals?
- What Are Computer-Style Progressive Lenses?
What Are Bifocals?
Bifocals are reading glasses that are clear at the top with a magnifying segment at the bottom.
Reading glasses help bring small text into focus through magnification, making text appear larger. Normal specs—what we call single-vision—magnify anything you view through the lens. Single-vision frames are great for reading, but if you want to look at something in the distance, you’ll need to take them off. Then, when you’re ready to read again, you have to put them back on.
Bifocals help solve this problem using glasses that only change part of your field of view. If you glance at something through the base of the lens, words will appear larger than normal; but if you look through the top of your glasses, objects appear as they would normally.
Types of Bifocal Lenses
What Are Traditional Bifocal Lenses?
- Most of the lens remains clear and magnification—free
- Small crescent at the base of the lens makes it easy to read small text
Benjamin Franklin is often credited with inventing the bifocal lens. While some historians disagree, it’s generally accepted that he was among the first to wear the specially—designed glasses.
Bifocals are actually the combination of two different kinds of lenses. In reading glasses, the larger lens does not change what the wearer sees at all, while a second, smaller lens is inset and offers the magnification, or diopter strength.
Over time, technology has improved bifocal lenses, but the basic design remains the same. Most of the lens allows you to see the world normally, while a small crescent adds the reading strength you need, where you need it. Bifocals allow you to comfortably shift between reading and looking at something in the distance, such as watching a favorite show on your TV.
What Are Progressive No-Line Bifocals?
- Top of the lens remains clear
- Strength of magnification gradually increases, giving you multiple focus points
- No-line design makes them ideal for sunglasses
In 1907, Owen Aves of England received a patent for progressive lenses. These specs offered a new take on Benjamin Franklin’s idea of having different magnification strengths in a single pair of glasses. Unlike traditional bifocals, however, progressives don’t have two lenses manufactured to fit in the frame. they are comprised of a single lens that changes magnification gradually.
This unique design means that the lenses have three levels of magnification. With reading glasses, the top is clear, allowing you to see things normally. Towards the middle, you get an intermediate magnification, gradually increasing in strength as your eye travels to the bottom of the lens. Since progressive glasses allow for multiple focus points, they can feel more versatile.
Another benefit of progressive lenses is their sleek, no-line design. Traditional bifocals are instantly identifiable thanks to the outline of where the two lenses meet. With progressives, the transition is seamless since there’s only a single lens, making these virtually indistinguishable from single-vision designs.
What Are Computer-Style Progressive Lenses?
- Top of the lens provides partial magnification, ideal for viewing text on a computer monitor
- Bottom of lens offers full magnification for reading small text
- Special anti-reflective coating helps limit the glare and additional strain artificial lights can put on your vision
Computers are a part of everyday life. Whether you’re working on a business document or catching up with loved ones over text or video chat, we spend a lot of our time in front of a computer monitor. Digital screens allow you to adjust the font size to one that’s more comfortable to read, but even so, prolonged reading off of an illuminated panel often causes eyestrain.
These glasses are designed with the needs of computer uses in mind. Unlike the progressive lenses found in most reading glasses, there is no “clear” or normal part to the lens. Instead, the top of the glasses offers 60% of the magnification strength, perfect for looking at text on a screen without making it overly large. The bottom of the lens offers full magnification for when you read the paper or other small text that can’t be modified.
To help mitigate the effects of harsh, artificial light, computer-style progressive lenses also come with a special anti-reflective coating, designed with computer monitors and fluorescent overhead lights in mind. The lenses will help minimize indoor glare, which can help reduce eyestrain. If you find that you use your reading glasses most when at a computer, these specialized progressives could be the lenses you’re looking for.
All eyewear mentioned above are non-prescription lenses and intended for generic use only.
Bifocal Readers FAQ
Can I buy non prescription bifocals?
Yes, you can purchase bifocals without a prescription.
Do bifocal reading glasses work?
Yes, bifocal reading glasses really work. In fact, they are excellent for both up-close vision and distance viewing, making them optimal for those who need to wear them all day.
Who invented bifocal readers?
Benjamin Franklin was said to have invented bifocal reading glasses in 1784.
Can I drive with bifocals?
Yes, you can safely drive with wearing bifocal reading glasses due to the magnification segment being near the bottom of the lens allowing for full, uncorrected distance viewing at the top.
Can I buy bifocal reading sunglasses?
Yes, bifocal reading glasses are available on the market. Shop bifocal reading sunglasses now!
How much do bifocal readers cost?
Bifocal readers can cost anywhere from $5 up to $500+ for designer brands.