As you age, your vision might deteriorate due to presbyopia or age-related farsightedness so that you require vision correction for objects that are either far or close. For example, when you begin having trouble reading or doing other activities such as threading, using a computer, or other activities, the time is ripe for corrective lenses. Depending on your needs and preferences, you can choose between bifocals or progressive lenses.
Bifocal spectacles have bifocal lenses that are made of two parts that are separated by a visible line. They were created by Benjamin Franklin when he cut two lenses and glued them to make one part in the eighteenth century. The two parts have different powers allowing you to see close things and things far away.
Bifocal lenses have two vision zones, the close-up and the far-away zones, and do not have a middle ground or an intermediate zone. The top focal spot is used to see things and objects far away, while the bottom focal area is used for objects and things up close, such as reading and threading a needle.
Traditionally, bifocal spectacles had a distinct and visible line separating the top and bottom lens. Manufacturers have since improved the lens appearance by creating different types with similar functionality.
The following are the different types of bifocal lenses:
- Flat-top/ D-Shape. The top of the lens is flat, and a distinct line separates the distant and near vision.
- Round segment. The lower part of the spectacles is curved, and the separating line is less distinct, making the spectacles appear similar to progressive lenses.
- Executive bifocal lenses. The bottom part of the lens has a magnifying lens for near correction, and they must be prescribed by a medical doctor an ophthalmologist.
Polarized sunglass bifocals provide wearers who have vision problems to see clear vision near and far away while providing superior protection from intense light. These sunglasses have special filters that reduce light intensity while providing tight and distance correction.
Progressive lenses have a single lens through which a wearer can see all distances. Simply put, progressive lenses have a single vision lens and no lines as opposed to bifocal lenses, where the lens is divided into two. They are also known as multifocal lenses because the wearer can see objects clearly from a single lens, whether near, intermediate or far.
Progressive lenses have different lens magnifications that provide a clearer vision for active wearers with three power zones ranging from near, intermediate, and far prescription for computer users and reading. There are different types of progressive lenses.
- Standard progressive. These lenses have three power zones and provide the wearer with an extensive view of all activities.
- Computer progressive. The glasses have lenses that protect your eyes when using the computer screen but cannot be used for daily wear.
- Ground-View progressive. The progressive lenses are suitable for daily computer users and persons who often look at the ground, such as athletes.
- Premium progressive. They are designed according to the wearer’s preferences and uses, considering their eyes and prescription, making them easier to adapt.
Differences between Bifocal Lenses and Progressive Lenses
While bifocal and progressive lenses have pros and cons, both advanced and bifocal lenses are manufactured to suit your unique needs and preferences as per your lifestyle and daily activities.
Bifocal lenses are best placed for reading materials over a long time, but they are not best placed for use on the computer screen as the user is likely to cause computer vision syndrome. On the other hand, Progressive lenses provide clear and better vision when using a computer and reduce eye strain when using the computer.
The following are the critical differences between bifocal and progressive lenses:
- Bifocal lenses have two vision lines, the top and bottom one for near and far away vision, while the progressive lens is a single lens that can see all distances.
- Bifocal lenses have a distinct line that separates the top and bottom focal zone, while the progressive lenses have a seamless progression with no distinction between the different lens powers.
- Bifocal lenses have only two vision zones; the near and far range, while the progressive lenses have clear vision at all distances, the immediate, intermediate, and far away.
When considering what lenses to purchase for your eye care, you must consult a doctor so that they recommend the lens that best suits your lifestyle and vision. Both bifocal and progressive lenses function similarly, and no matter what choice you make as per your lifestyle and preferences, they will cater to your eyesight. Where you purchase a bifocal or a progressive lens, ensure you stick to one pair and avoid switching between the pairs until your eyesight changes.