SINGLE VISION LENSES
SINGLE RX
A singular lens that can improve distance or reading. With only one vision correction, this everyday lens can either correct nearsightedness or farsightedness.
Single Vision Lenses
It wasn't until the 17th century that people discovered the principles of single vision lenses. They discovered that concave and convex lenses improve two common types of vision deficiencies. They realized that a concave-shaped glass lens improves nearsightedness while a convex-shaped glass lens improves farsightedness. These design principles have helped generations with their vision impairments.
Presently, single vision lenses are the most common lens. Approximately 64% of adult Americans wear glasses or will need a pair in the future. Frequently, most adults in their 20s and 30s have problems with nearsightedness or farsightedness; the two most common vision impairments. Since these lenses improve people's reading skills and allow them to see distant objects more clearly, most adults can be seen wearing this type of lens.
Single vision lenses have little to no adjustment period and are also the most affordable lens type. The cost can vary, but ranges from $5-$500, while the cheapest ranges from$15-$100. Over-the-counter reading glasses are often the most affordable and are for those with minimal impairment to their vision, but generally don't offer as clear a picture as purpose-made lenses.
Varying on the level of impairment, it is recommended to get a prescription. Buying single vision lenses, or other types of lenses, without a proper prescription, can further damage someone's eyes.
When it comes to eye safety, it is recommended that polycarbonate or trivex lenses are used as they are the safest material for eyeglasses, sunglasses, and sports eyewear. Plastic lenses provide equal protection and are much lighter, but can be easily scratched.
Costs may rise depending on the lens material, and index (thickness). For people who have strong prescriptions, the prices can increase significantly for their lenses. Single vision lenses can only correct one vision depth, though, for people who need multiple vision depths corrected, they should consider either bifocal or trifocal lenses. No matter which glasses you need, you can be assured that our knowledge and technology have come a long way since 1784.
LINED BIFOCAL LENSES
MULTIFOCAL
A lens that separates near and far visions with a visible straight line. The bottom region improves close objects as the top corrects distant objects. Typically used for reading, lined bifocal lenses are usually prescribed to wearers who have trouble adjusting to progressive no-line bifocal lenses. The bifocal area is usually 28mm wide.
Flat top 28 bifocal glasses lenses offer correction for both near and far distances. It is a multifocal lens commonly prescribed for those suffering from both presbyopia and hypermetropia, a condition whereby, with age, the eye exhibits a progressively diminished ability to focus on near and far objects. The flat-top lens includes a segment at the lower half of the lens with a prescription for reading (near distance). The width of the flat top 28 bifocal is 28mm wide at the top of the bifocal and looks like the Letter D turned 90 degrees.
Because the flat top 28 bifocal lenses are one of the easiest multifocal lenses to adapt to, it is one of the most popular bifocal lenses in the world. Its distinct “jump” from distance to near vision gives wearers two well-demarcated areas of their glasses to use, depending upon the task at hand. The line is obvious because the change in powers is immediate with the advantage being it gives you the widest reading area without having to look too far down the lens. It is also easy to teach someone how to utilize the bifocal in that you simply use the top for distance and the bottom for reading.
Look for the Bifocal FT-28 in the Lens Options field when ordering your bifocal glasses.
Available in these LENS MATERIALS:
• Glass
• Polycarbonate
• Trivex
• CR-39
• High Index
Available in these LENS TINTS:
• Transitions Gray and Brown
• Drivewear: Yellow to Dark Red Brown
• Polarized Gray and Brown
• Fixed Tints, such as Tan C, Pink, Green, Gray, Yellow, and more
NO-LINE PROGRESSIVE BIFOCAL LENSES
MULTIFOCAL
A bifocal lens without a visible line creates a smoother transition between each region. This bifocal lens improves vision of distant objects in the top region as the bottom improves intermediate and nearsighted visions. The no-line bifocal lens is cosmetically appealing to wear as there is no visible line.
All About Progressive No-Line Bifocal lenses
The reason why progressive no-line bifocal lenses were created was for cosmetic purposes so people could have an appealing alternative to the traditional lined bifocal lenses. These lenses are far more technical than a standard lens.
When we think of vision, there are three distinct distance ranges: near for reading or working up-close to your face, intermediate, for anything at arm's length, and distance, for things that are farther away. Not many prescribed lenses can fix all three visions at once except for a progressive no-line bifocal lens.
A no-line bifocal lens is the modern lens that strays away from its predecessors. It is without a visible line, creating a smoother transition between each region.
The regions are like those inlined bifocals except that the edges of the lens are considered a dead spot. The top region of the lens corrects distant objects, while the bottom portion of the lens corrects intermediate and up-close objects.
A wearer may prefer bifocals without lines if they do not appreciate lined bifocal lenses; having a visible line in the lenses can be distracting to some. It can be more cosmetically appealing to wear and less strenuous on the eye. Plus, instead of owning multiple prescribed glasses, wearers can own only one pair with no-line bifocals.
Progressive lenses are recommended for people who suffer from nearsightedness, farsightedness, and/or astigmatism. As much as progressive bifocals are beneficial, there are some disadvantages.
The cost of progressive lenses can be pricey compared to other lens types. Some people are more acquainted with a lined bifocal lens and have trouble adapting to progressive lenses. It may affect the wearer's peripheral vision at the edge of the lens which can cause people to become disoriented or nauseous. Most people will adjust to the distortion quickly and some have higher sensitivity in their peripheral vision and have trouble adjusting. For people who have trouble adjusting, lined bifocals are recommended.
