Single Vision, Bifocal, and Progressive Lenses: What Are the Differences?
When you get glasses, you have several types of lens options depending on your prescription. But many people get confused by the terms single vision, bifocal and progressives. These terms refer to how the lenses in your glasses are designed and are based on your prescription. But if you are not sure about what type of glasses your prescription requires, here is a quick overview to help you get started.
A single vision lens is essentially a lens that holds one prescription. This type of lens is used for prescriptions for people who are nearsighted, farsighted, have astigmatism, or have a combination of refractive errors. In many cases, single vision glasses are used by people who need the same amount of power to see far away and close up. However, there are single vision glasses prescribed for a specific purpose. For example, a pair of reading glasses that are used only for reading contains a single vision lens.
The single vision lens is ideal for most children and younger adults because they typically don’t need to adjust their vision correction based on their distance. Your single vision glasses prescription always includes a spherical component as the first number on your prescription and may also include a cylinder component to correct for astigmatism.
If your doctor mentions presbyopia, they are talking about the age-related change to your eye’s focusing power. While you can correct presbyopia with single vision glasses specifically for reading, most people like to have one pair of glasses that allows them to see through two different fields of vision.
Bifocal glasses essentially do this by combining your distance prescription and your near prescription. In bifocal glasses, the bottom of the lens has a segment with extra power that lets you read with ease. The bifocal has a prominent line that separates the near and distance portion and that line is visible to others.
Progressive eyeglass lenses are also called a no-line bifocal because they have no visible line between the segments, which makes them more aesthetically pleasing. Moreover, progressive eyeglasses also create a smooth transition between the distance, intermediate, and near portions of your prescription. The intermediate portion of the lens is ideal for mid-range activities such as computer work. Progressive eyeglasses have the option of a long or short corridor design. The corridor is essentially the part of the lens that gives you the ability to see intermediate distances.
Whether your prescription requires a single vision, a bifocal, or a progressive lens design, you can find the glasses you need at VisionExpress.ph. When browsing our collection, you can choose from a variety of lens materials as well as several coatings, such as an anti-reflective coating to avoid glare or transitions lenses that protect your eyes from the sun when you venture outdoors. In some cases, your optometrist may recommend specific lens design based on your need and your ocular health status.