Normal lenses often create glare, reflections, and “ghost images.” Now these can be eliminated with an anti-reflective coating. With normal glasses, much of the light reflects off the lenses. This
produces glare. It also reduces the wearer’s visual acuity. In other words, the light reflections are a cosmetic and visual problem.
Anti-reflective coatings increase light transmission through the lenses to 99.5 percent. It makes it easier to see and easier for others to see you. These coatings are especially useful for those viewing computer screens and driving at night.
For many people, different lenses are needed for seeing at different distances. Bifocal lenses allow the wearer to look through two areas of the lens. One area focuses on distant objects. The other is used for reading.
Most of the time the “reading” area is smaller, shaped like a sideways “D”, and found in the lower half of the lens. These bifocals are called lined or straight top bifocals. If you are focusing on distant objects, you look through the top half of the lenses. To read a book, or newspaper, you look through the “reading” area. One common complaint with using bifocals is dealing with the line between the two areas.
Fortunately, recent technologies have developed a new type of lens, called the no-line, or progressive lens.
Cosmetic and Specialty Tints
Eyeglasses can be a stylish accessory, a part of your personality, or a way for you to be different. There are a variety of frames to choose from, but you may not know that there are a variety of ways to improve the appearance of the lenses, too. Cosmetic tints are available in a variety of colors and shades. Some lenses are clear at the bottom and gradually get darker towards the top of the lenses. There are many ways to adjust your lenses to suit your personality. Some tints are also functional.
High Index Lenses
Until recently, the only materials available to use for lenses were glass and a hard resin called CR-39. Recently though, high index lenses have become available. High index materials are named because they have a higher index of light refraction than CR39. Basically, they can do the same job that glass or CR39does, but high index lenses are much thinner and lighter. With high index lenses, you can avoid having “soda bottle” lenses.
When speaking about high index lenses, you may hear many unfamiliar numbers and terms. Here are a few things to remember:
The first and still most popular high index plastic is polycarbonate. Polycarbonate was originally developed for fighter jet cockpits. It is very strong, very light, and impact resistant. Most sports lenses are made of polycarbonate.
Other high index materials are classified by numbers. The higher the number, the thinner and lighter the lens. The lower numbers are such as 1.54, 1.56, and 1.57 are classified as mid-index. These lenses are thinner than glass, and nearly as strong as CR-39.
High index lenses, such as 1.66, 1.74, and 1.9, are much thinner than regular glass or plastic. Talk with your doctor to decide which high index lens is right for you.
One of the main problems with bifocals is the problem of eye fatigue. Many people have difficulty switching between the two focusing powers of the lined bifocals. Your eyes become tired, which in turn can even lead to a headache, sore neck and sore back.
A recent variation of bifocals is called no-line or progressive lenses. No-lines provide a smooth transition from focusing on nearby to focusing on distant objects because they do not have a distinct line which separates the focusing powers. Instead, a gradual change in power allows the wearer to focus on objects at all distances. Distant objects are viewed through the upper portion of the lens, while near objects are viewed through the middle or lower portion of the lens. These are also great for computer users.
If you have ever felt frustrated at needing prescription glasses and prescription sunglasses to accommodate an outdoor lifestyle, you should consider photochromatic lenses. Photochromatic lenses darken when exposed to UV rays. When the wearer goes outside, the lenses darken or tint. When the wearer goes back inside, the glasses become clear.
There are a variety of photochromatic options available. Depending on what you choose, you can customize the lenses to your needs. Some lenses darken only in direct sunlight, while others darken in little or no direct light. Some are designed to darken while you are in the car to reduce road glare while you are driving. You can even choose the color of the tint. Ask your doctor what options are available.
Glare from wet roads, light reflecting off other vehicles, and glare from your own windshield can be annoying and dangerous. To eliminate this glare, we offer polarized lenses. Polarized lenses eliminate almost all glare, reducing eye strain and increasing visibility. Polarized lenses are the most effective way to reduce glare. Most glare comes from horizontal surfaces, so the light is “horizontally polarized.” Polarized lenses feature vertically-oriented “polarizers.” These polarizers block the horizontally-polarized light. The result is a glare-reduced view of the world. Polarized lenses can make a world of difference for any outdoor enthusiast.
Fisherman can eliminate the bright reflections from the water and actually see into the water more easily than with any other sunglasses, golfers can see the green easier, and joggers and bikers can enjoy reduced glare from the road. In addition, drivers can enjoy the safety and comfort that polarized lenses provide while driving.
Scratch Resistant Coating
If you have hard resin lenses (CR-39), you should consider getting a scratch resistant coating. Resins and plastics are more susceptible to scratches than glass. Scratches damage the cosmetic look of the lenses as well as their performance. With a scratch resistant coating, you don’t have to worry so much about minor scratches on your lenses.
Another advantage of scratch resistant coatings is that most coatings come with a one-year warranty. They are a great investment to prevent minor scratches. However, it is important to remember that scratch resistant does NOT mean scratch-proof. All lenses are susceptible to scratches.
We all have heard the phrase, “Different strokes for different folks.” Well, this holds true in terms of selecting glasses. There are different lenses for just about anybody. No matter what your
particular need, there is probably a specialty lens designed for you.
For example, a specialty lens that is becoming increasingly useful is designed for computer users. Computer lenses have “windows” designed for viewing your computer screen, documents on your desk, and distant objects. The lenses are designed to reduce Computer Vision Syndrome, or CVS, which is characterized by headaches, eye strain, neck and back aches, dry eyes, blurred vision, and double vision.
Another example is called the double D-segment lens, also known as the double straight-top lens. If you look through most of the lens, you can focus on distant objects. But you can also look through a D-shaped segment near the top of the lens to see nearby overhead objects more clearly. This is very useful if you are involved in work where you’re looking at nearby objects above your field of vision, as with carpenters and pilots. The D-shaped segment near the bottom of the lens allows for reading.
Bifocals allow the wearer to read through one area of the lens, and to focus on distant objects through another area of the lens. As the eyes age, though, a stronger prescription is needed to read. This would be fine, but the stronger prescription that allows for reading makes it difficult to focus on objects at intermediate distances, such as grocery items on a shelf or your speedometer. Thus, trifocals are necessary for a third prescription for intermediate focusing.
Trifocals, also known as lined trifocals, feature three areas of focusing power, each separated from the other by a distinct line. The three windows allow for focusing on distant objects, intermediately distanced objects, and for reading. The downside of trifocals is dealing with the lines between the different focusing powers. Fortunately, recent advances in technology have led to developments in no-line, or progressive lenses.